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Review

Assessing Early Childhood Sustainability Apps: A Dual-Framework Evaluation

by
Sin Chun Ng
1,
Ka Lee Carrie Ho
2,
Chung Man Tang
1,*,
Man Fai Leung
1,*,
Yat Him Lee
1 and
Siu Nam Chan
1
1
School of Computing and Information Science, Faculty of Science and Engineering, Anglia Ruskin University, Cambridge CB1 1PT, UK
2
School of Education, Faculty of Arts, Humanities, Education and Social Sciences, Anglia Ruskin University, Chelmsford CM1 1SQ, UK
*
Authors to whom correspondence should be addressed.
Sustainability 2026, 18(1), 299; https://doi.org/10.3390/su18010299 (registering DOI)
Submission received: 13 November 2025 / Revised: 18 December 2025 / Accepted: 24 December 2025 / Published: 27 December 2025
(This article belongs to the Section Sustainable Education and Approaches)
Versions Notes

Abstract

(1) Background: using an artefact-based secondary analysis approach, this paper critically reviews eleven mobile applications designed for early childhood sustainability education. (2) Methods: the study employs a dual-framework evaluation rubric, based on Parsons and Ryu and on Ozdamli, which assesses ten criteria, including pedagogical approach, accessibility, and interdisciplinary integration. Two independent reviewers scored each app, with inter-rater reliability confirmed via Cohen’s kappa (0.74–1.00). (3) Results: results reveal a strong bias towards environmental SDGs, limited accessibility features, and minimal teacher-facing tools. Only one app addressed all three sustainability pillars: environmental, social, and economic. (4) Conclusions: the paper proposes AI-enhanced design strategies and culturally responsive workflows to improve app effectiveness. Recommendations include embedding interdisciplinary task flows, multilingual scaffolds, and community-linked challenges to support transformative sustainability learning in early childhood education.

1. Introduction

Agenda 2030, adopted by the United Nations (UN), articulates 17 Sustainable Development Goals (SDGs) aimed at addressing global challenges, including climate change, equality, and poverty [1]. Embedding these principles early in life is critical for achieving long-term sustainability [2,3]. Early childhood education (ECE), defined by UNESCO as organised learning from birth to age eight [4], plays a foundational role in shaping cognitive, social, and ethical dispositions. ECE not only supports holistic development but also cultivates sustainability awareness, positioning young children as active contributors to sustainable societies [4,5,6].
Digital technologies, particularly mobile learning (M-learning) [7], offer transformative potential for ECE by enabling interactive, flexible, and context-aware experiences [8,9]. Mobile apps can embed sustainability concepts into playful, inquiry-based tasks [10], yet their integration into curricula remains uneven due to pedagogical resistance and limited teacher training [7,11,12]. Despite increasing interest in sustainability education, few studies critically examine whether mobile applications for ECE address all three sustainability pillars—environmental, social, and economic—or align with transformative pedagogies [13]. Current apps often prioritise environmental themes, neglecting cultural and economic dimensions, accessibility, and teacher-facing features. This review is situated within transformative sustainability education (TSE) [14,15] and informed by a posthumanist lens that values children’s relational engagement with non-human life [16,17].
The United Nations Educational, Scientific and Cultural Organisation [18] asserts that children have a right to participate in sustainable practices, a principle echoed by historical educators such as Maria Montessori and Rudolf Steiner, who advocated for environments that promote social justice, peace, and equality [19,20]. Despite these recommendations, significant barriers persist in integrating education for sustainability (EfS) into early childhood curricula. Although teachers recognise the importance of EfS, the focus of curricula on literacy and numeracy limits the time available for sustainability education [21]. These structural constraints, combined with the influence of teachers’ environmental attitudes [22], shape both classroom practice and the design of digital learning tools.
Research highlights the importance of dialogic interaction and play-based pedagogies in empowering children’s active participation in sustainability discussions [23]. However, many educators neglect the economic and cultural pillars of sustainability outlined in the Brundtland Report [24], focusing instead on environmental aspects, a tendency that risks tokenistic implementation [13,25]. Comparable to resistance towards M-learning, educators often hesitate to adopt sustainability practices due to limited training and conceptual clarity [12,26]. Some early childhood practitioners assume that exposure to nature alone suffices for EfS, overlooking the need for structured strategies [27].
Classroom-level barriers in ECE, including curricula overload, lack of institutional support, and underemphasis on social/economic SDGs, help explain why sustainability apps frequently prioritise environmental themes over a holistic approach [21,26]. The literature further stresses that effective EfS should progress beyond awareness to transformative action [14,15] and adopt relational approaches that value children’s engagement with non-human life [16,17]. These insights provide critical benchmarks for evaluating whether app features, such as prompts, reflection tools, and collaborative functions, enable child agency rather than passive consumption. This study provides actionable insights for developers, educators, and policymakers to enhance sustainability learning through mobile apps in early childhood contexts. To address these gaps, this study evaluates early childhood sustainability apps using a dual-framework rubric. It asks the following questions:
RQ1: to what extent do existing mobile applications for early childhood education address the full scope of the Sustainable Development Goals?
RQ2: how do these applications perform across key design and pedagogical criteria?
RQ3: what gaps exist in accessibility, interdisciplinary integration, and stakeholder support?
RQ4: what design recommendations can be made to enhance transformative sustainability learning through mobile apps?

2. Materials and Methods

This study employed an artefact-based evaluation of early childhood sustainability apps guided by an enriched theoretical framework combining mobile learning design and pedagogical principles. The evaluation rubric was initially based on [28] the mobile learning design framework and [29] the pedagogical model, which remain foundational for assessing usability, collaboration, and integration of tools. To ensure contemporary relevance, these were extended with recent scholarship on mobile learning adoption and effectiveness [11,12], inclusive design and accessibility standards [30,31], and sustainability pedagogy in early childhood [32,33,34]. Additional insights from culturally responsive education [35,36] and interdisciplinary approaches [10,17] informed the rubric to reflect global trends in eEfS. This integration ensures that the evaluation criteria address inclusivity, multilingual scaffolds, ethical design, and transformative learning outcomes.

2.1. Procedures and Data Collection

The study adhered to international research ethics guidelines [37]. User testing was excluded to comply with UNCRC Article 12 [38] on safeguarding children’s participation rights, focusing instead on artefact-based analysis of app functionality rather than behavioural outcomes.

2.1.1. Selection of Apps

Apps were restricted to English-language and free or freemium models to promote equitable access for educators in resource-constrained contexts, consistent with UNESCO GEM principles on inclusive education [36]. Paid apps were excluded to prevent socioeconomic bias that could undermine SDG 4.7 commitments to equity [1]. English was chosen for feasibility and consistency in applying the evaluation rubric, though this introduces cultural and linguistic bias. App availability is further influenced by geographical and legal constraints, including data protection laws (e.g., GDPR) [39], censorship, and territorial licensing, which segment access across regions [40,41,42]. Consequently, the sample reflects apps accessible in unrestricted markets, limiting global representativeness.
To ensure consistency across platforms, identical keywords—“sustainability,” “environment,” and “early childhood”—were applied in searches on Google Play and the App Store. When discrepancies occurred due to platform-specific algorithms, minor adjustments were made while preserving inclusion criteria. This iterative tuning reduced algorithmic bias and ensured comparability in app retrieval. Inclusion criteria wer (1) relevance to sustainability and ECE, (2) English-language availability, and (3) free or freemium model. Eleven apps met these criteria (Table 1 and Table 2). Two researchers independently reviewed the apps, resolving discrepancies through discussion. The platforms on which the reviewed applications are available (App Store, Google Play, or both) are summarised in Table 3.

2.1.2. Comparison of Existing Apps in the Market

The rubric integrates classic frameworks [1,2] with recent insights on mobile AR and inclusive design [10,30] (Table 4). To review mobile learning tools systematically, the evaluation rubric was constructed by mapping criteria to two established frameworks. Parsons and Ryu [28] emphasise five design-oriented factors: (1) user role and profile, (2) learn on the move, (3) interface design, (4) media types, and (5) collaboration support. From a pedagogical perspective, Ozdamli [29] proposed four criteria for integrating mobile tools into teaching: (1) integration of tools, (2) pedagogical approaches, (3) assessment techniques, and (4) teacher training. These were included to reflect teacher needs as key stakeholders [7]. Accessibility was added as a tenth criterion to address inclusive design and equity for learners with disabilities. Collectively, these ten criteria were selected for their relevance to mobile learning and early childhood pedagogy rather than alternative indicators that lacked direct applicability. Accessibility was assessed against inclusive design principles, and interdisciplinary integration was examined to determine whether apps link sustainability concepts with other domains such as literacy and numeracy [33,34,43].
Incorporating recent research ensures alignment with current trends in mobile learning, accessibility standards, and culturally responsive sustainability education [10,35,36].

3. Results

This section synthesises findings from the artefact-based evaluation of eleven early childhood sustainability apps. Rather than presenting app-by-app descriptions, results are organised into thematic clusters reflecting cross-app patterns in SDG coverage, accessibility, pedagogical alignment, assessment, mobile-specific affordances, and usability. Comparative insights are supported by rubric scores and summary tables (Table 5, Table 6, Table 7, Table 8, Table 9, Table 10, Table 11, Table 12 and Table 13), enabling readers to interpret systemic trends and performance bands across the sample.

3.1. SDG Coverage and Thematic Bias

SDG coverage was coded for both breadth (number of SDGs referenced) and depth (extent of pedagogical integration). Operationalisation was recorded only when an SDG was linked to interactive tasks, inquiry sequences, or reflective prompts rather than static mentions. As shown in Table 5, SDG 12 (Responsible Consumption and Production) is the most prevalent, appearing in nine apps, reflecting a strong emphasis on sustainable consumption practices. SDG 13 (Climate Action) follows closely with eight apps, indicating climate mitigation as a dominant theme. In contrast, SDG 15 (Life on Land) occurs in six apps, often through informational content (e.g., biodiversity facts quizzes) rather than interactive, action-oriented features. Social and economic SDGs (e.g., SDG 1 (No Poverty) and SDG 10 (Reduced Inequalities) are represented in only two to three apps, and primarily in static or representational form (diversity symbols), limiting opportunities for transformative learning and participatory engagement [13,26,36]. Environmental dominance is compounded by shallow operationalisation: most apps reference SDGs in static content rather than embedding them in inquiry-based or collaborative tasks [15,36].

3.2. Accessibility and Equity

Accessibility features are minimal (rubric mean, 1.7/5). No app demonstrates WCAG 2.1 AA conformance; text to speech, scalable typography, captions and contrast controls are largely absent. Multilingual provision appears in menu-level localisation in a minority of apps and seldom extends to instructional content (Table 6 and Table 13). These gaps conflict with inclusive design/UDL guidance and web accessibility standards, constraining participation for disabled learners and emergent bilinguals [30,31,36].

3.3. Pedagogical Alignment and Child Agency

Most apps privilege information delivery and quiz-style tasks over inquiry/play-based sequences; only one app consistently blends inquiry, reflection, and dialogic elements (Table 6 and Table 7). The resulting extraneous cognitive load (text-heavy screens, abstract metrics) and limited child agency/collaboration are misaligned with ECE and learning-sciences principles [44,45]. As prior reviews note, such tools tend to elicit recall/performance rather than exploratory learning aligned to developmentally appropriate practice [11,13].

3.4. Assessment and Teacher Support

Assessment clusters around summative scoring and leaderboards; formative constellations (feedback, success criteria, reflective prompts) are scarce, with only one app offering a teacher dashboard (Table 8 and Table 9; see app-level summary in Table 13). Mean rubric scores corroborate the gap in teacher-facing supports and assessment. Points/stages may lift participation but are associated with surface outcomes absent explicit guidance on next steps [46,47]. Lack of planning templates, analytics, and exportable evidence further reduces classroom uptake [11].

3.5. Mobile-Specific Affordances (“Learn on the Move”)

Mobile-specific affordances are underutilised. Few titles leverage camera, audio, GPS, or context-aware prompts for situated eco-tasks; where present, features are often performance-gated or require abstract carbon calculators misaligned with ECE developmental levels (Table 10). Overall suitability reflects this pattern (Table 10). Since mobile learning is most effective when tasks are situated, multimodal, and experiential, these omissions are material [9,11]. Where context awareness is envisaged, design should adopt privacy by design appropriate to children’s data [39,48].

3.6. Usability and Onboarding Frictions

Common frictions include intrusive adverts, paywalls, dense text blocks, and small tap targets, elevating extraneous cognitive load and interrupting flow [44,49,50]. Mandatory accounts and abstract numeracy inputs at onboarding further reduce accessibility for young learners and busy teachers. Platform context is shown in Table 4, Table 5 and Table 6. Early-years-appropriate onboarding should minimise steps to first activity, defer registration, and favour icon-supported guided discovery [44].

3.7. Comparative Performance Bands (High/Medium/Low)

Aggregating unweighted rubric scores (range 10–50) yields three bands (Table 13): high (one app integrating inquiry, journalling and a dashboard), medium (partial alignment on media/interface but weak assessment/teacher supports), and low (static content/minimal affordances). Sensitivity checks using alternative weights preserved top/bottom quintiles, indicating rank-order stability [51,52]. Across bands, decisive discriminators are accessibility, formative assessment, and teacher-facing supports rather than content volume or gamification.

3.8. Synthesis: Systemic Gaps and Opportunities

Three cross-cutting gaps dominate: (i) SDG breadth–depth imbalance favouring environmental themes; (ii) weak inclusion infrastructures (accessibility, multilingual scaffolds); and (iii) limited formative/teacher supports. Together, these cap learning at awareness-level and individual performance rather than collaborative inquiry and action [13,26]. Opportunities include WCAG-aligned multimodality/UDL, embedded formative progression and dashboards, and situated mobile tasks with privacy by design [31,36,48].
Across the 11 evaluated apps, environmental themes overwhelmingly dominate, while social and economic dimensions of sustainability are largely absent. Accessibility features remain minimal, with no app achieving WCAG 2.1 compliance, and multilingual scaffolds are rare. Teacher-facing supports and formative assessment tools are similarly underdeveloped, limiting classroom integration. These systemic gaps indicate that current app ecosystems prioritise static content and gamification over inclusive, inquiry-based, and culturally responsive design.

3.9. Evaluation Rubric and Reliability

To enhance the methodological rigour, each app was evaluated using a structured 1–5 rubric across ten criteria spanning mobile learning design and pedagogy [28,29]. Two reviewers, who held MSc degrees in ICT and applied data science and professional experience in software QA testing, rated independently following a brief calibration exercise (codebook with examples); disagreements were resolved by discussion after reliability estimation. Inter-rater reliability was calculated per criterion using weighted Cohen’s kappa appropriate for ordinal data, with 95% confidence intervals [53,54]. Rubric was constructed for content validity by mapping items to the two frameworks and to TSE constructs, and for construct validity, it was constructed by aligning child agency and teacher support indicators with the literature [14,15,23]. To enhance transparency and reproducibility, a worked example illustrating how the scoring rubric was applied to a specific app is provided in Appendix B.

3.9.1. Scoring Rubric (1–5; Ordinal Anchors, Table 11 and Table 13)

Each criterion was rated on a five-point ordinal scale: 1 = poor: feature is absent or severely limited; 2 = fair: feature is present but underdeveloped/inconsistent; 3 = good: feature is functional and moderately effective; 4 = very good: feature is well integrated and user-friendly; 5 = excellent: feature is exemplary, innovative, and pedagogically robust.
Note: ratings are ordinal; distance between adjacent categories is not assumed to be equal.

3.9.2. Criteria Evaluated

Learn on the move, user role and profile, interface design, media types, collaboration support, integration of tools, pedagogical approach, assessment techniques, and teacher-facing supports/CPD were evaluated. Accessibility criterion definitions and exemplar indicators are provided in the codebook (Appendix A).

3.9.3. Inter-Rater Reliability Metrics

Weighted Cohen’s kappa was computed for each criterion (Table 12) [53].

3.9.4. Summary of Performance and Aggregation

Total scores were calculated as the unweighted sum of ten criteria (range: 10–50) (Table 13). We adopted this approach to ensure transparency and comparability across dimensions, consistent with prior mobile learning evaluation studies [28,29]. Although accessibility and teacher-facing supports are pedagogically critical, weighting these would require normative judgments that vary by context. Sensitivity checks using alternative weights (design: pedagogy = 40:60; accessibility × 1.5) produced identical top and bottom quintiles, indicating that unweighted aggregation did not distort rank ordering. This method aligns with recommendations for ordinal rubric scoring, where clarity and reproducibility are prioritised over complex weighting schemes [51,52]. No missing ratings occurred.

3.9.5. Criterion Means (Interpretive Summary)

Learn-on-the-move (3.1) and media/interface (≈3.3–3.5) are adequate, whereas collaboration (2.8), assessment (2.9), teacher-facing supports (2.4), and accessibility (1.7) are systemically weak—aligning with prior evidence that many learning apps favour information delivery and gamification over formative scaffolding and inclusion [31,39,40].

3.9.6. Limitations and Future Reliability Work

Reliability estimates may be affected by the small number (n = 11) of apps and skewed distributions on some criteria. Future studies should (i) pre-register codebooks; (ii) increase app samples; (iii) report weighted κ with CIs (confidence intervals) plus Gwet’s AC/Krippendorff’s α; and (iv) provide item-level histograms to provide evidence of rater use of the scale [51,52,55,56,57]. It should provide a concise and precise description of the experimental results and their interpretation, as well as the experimental conclusions that can be drawn.

4. Discussion

This review shows that the current ecosystem of ECE sustainability apps is underdeveloped in scope and depth. Learn on the move (3.1) and media/interface (≈3.3–3.5) are adequate, whereas collaboration (2.8), assessment (2.9), teacher-facing supports (2.4), and accessibility (1.7) are systemically weak—aligning with prior evidence that many learning apps favour information delivery and gamification over formative scaffolding and inclusion [31,39,40].

4.1. Equity, Accessibility, and Cultural Responsiveness

The low accessibility mean (1.7/5) reflects systemic gaps in WCAG-aligned features such as text to speech, font scaling, contrast options, and captions, limiting participation for disabled learners and emergent bilinguals and conflicting with UNCRC Article 12 on children’s rights to be heard [31,38]. Accessibility should be treated as both a design criterion and an ethical threshold for equitable eEfS [30,31]. Normatively, ECE-facing apps should incorporate device-level text to speech, scalable typography, high-contrast themes, icon-plus-text labelling, multilingual scaffolds, and teacher-side controls.
Persistent gaps often stem from practical barriers. Technically, mobile contexts require complex adaptations for small screens, gesture-based navigation, and assistive technology interoperability; WCAG 2.2 addresses many of these issues, but consistent implementation across platforms demands specialised design and testing [31]. Financially, compliance entails investment in inclusive design systems and accessibility QA, now mandated under the European Accessibility Act (EAA) from June 2025 [58]. Linguistically, UNESCO reports that 40% of learners lack access to education in a familiar language, underscoring the need for home-language audio, dual-language prompts, and culturally localised examples [36,59].
Cultural responsiveness remains limited despite its importance for global citizenship. Beyond environmental themes, apps should embed social and economic dimensions through age-appropriate, culturally grounded tasks. Examples include interactive role-play about sharing resources (SDG 6, SDG 10) and gamified “pretend markets” teaching fair exchange and resource allocation (SDG 12, SDG 8). These approaches align with experiential learning principles [45] and culturally responsive pedagogy [35], enabling children to situate sustainability within their lived experiences rather than abstract concepts. Detailed examples of culturally grounded, app-based tasks are provided in Section 4.5.

4.2. Teacher-Facing Design and Adoption

Consistent with prior studies on mobile learning adoption, most apps prioritise learners while neglecting teachers and administrators, offering few planning templates, formative dashboards, or multilingual guides [7,12]. This aligns with documented barriers, time pressure, confidence gaps, and lack of exemplars, which impedes embedding EfS across core subjects [21,26,60]. The low rubric mean for teacher-facing support (2.4), a finding mirrored by the scarcity of planning templates and dashboards in the app-level summary, indicates a design gap that directly affects classroom uptake; embedding ready-to-use interdisciplinary sequences, formative assessment tools, and CPD micro-modules would address these constraints.
Teacher-facing features should be structured for usability and workload management. Teacher dashboards should prioritise simplicity and clarity to accommodate diverse levels of digital literacy. Recommended design principles include (i) progressive disclosure—start with essential functions (e.g., class overview, SDG-linked tasks) and allow optional advanced features; (ii) visual analytics using icons and colour coding rather than dense tables; and (iii) embedded exemplars (sample lesson flows, reflection prompts) aligned with local curricula to reduce planning time. Planning templates should integrate sustainability tasks into existing subjects (e.g., literacy, numeracy) to avoid curriculum overload, consistent with evidence that teachers face significant time constraints and confidence gaps in EfS integration [21,26,60]. Research on mobile learning adoption highlights that perceived ease of use and workload reduction are critical for uptake [11,12]. Dashboards should therefore include one-click export for evidence portfolios, offline-first operation, and micro-CPD modules to support ongoing professional learning without adding extra sessions.
Collaboration features should be designed as closed, teacher-controlled spaces that support co-documentation (photo, voice, drawings), turn-taking prompts, and consent-aware sharing, in line with children’s data protection principles [39,48].

4.3. Assessment: From Scores to Formative Progression

Only ECE Academy—Sustainability provides a formative assessment constellation (feedback, journalling, teacher dashboard). In contrast, several titles rely on gamified scoring/leaderboards, which may drive participation but tend to produce surface-level outcomes without guidance on the next steps. Behaviour-change features (goal setting, carbon tracking) in Klima—Fight Climate Change and Earth Hero: Climate Change similarly lack educational scaffolding. To align with learning evidence, apps should provide success criteria, hints, exemplars, and reflective prompts, coupled with teacher mediation, to support progression (cf. the rubric results; see also [29]).

4.4. Historical Evolution and Pedagogical Evidence

To contextualise the analysed applications, we compiled release dates, update histories, and major feature modifications (see Table 14). Most apps were launched between 2015 and 2022, with update cycles ranging from frequent (e.g., Earth Hero: Climate Change, updated quarterly to include multilingual menus) to stagnant (e.g., Environmental Studies Notes, last updated in 2018). Feature evolution reveals incremental improvements in interface design and gamification but limited progress in accessibility and teacher-facing tools. Notably, none of the apps introduced comprehensive WCAG 2.1 compliance or culturally responsive scaffolds during their update histories, indicating a persistent gap in inclusive design despite regulatory and pedagogical imperatives [31,36]. Tracking these trajectories highlights a misalignment between app evolution and transformative sustainability education principles, which emphasise play-based inquiry, cultural relevance, and child agency [13,35].
Beyond design trends, empirical evidence underscores the pedagogical potential of mobile learning when developmentally appropriate. Systematic reviews report that mobile apps can enhance engagement and conceptual understanding in early childhood, particularly when multimodal scaffolds and inquiry-based tasks are embedded [11]. Recent studies on augmented reality and sustainability education demonstrate gains in motivation and collaborative problem solving among preschool learners [10]. Similarly, interventions integrating mobile tools into eco-literacy programs have shown positive effects on pro-environmental behaviours and dialogic learning [27]. These findings reinforce the need for apps to progress beyond static content and gamified scoring toward formative, culturally grounded experiences that foster agency and interdisciplinary thinking.
Future research should examine whether update cycles correlate with improvements in accessibility, multilingual support, and teacher mediation and should link these design changes to measurable learning outcomes through classroom-based trials and longitudinal studies. Explainable AI mechanisms should be embedded to ensure transparency in adaptive recommendations, enabling teachers to interpret algorithmic logic. Bias risks must be mitigated through diverse training datasets and fairness audits. Compliance with GDPR and the ICO Children’s Code is essential, requiring privacy-preserving architectures and parental consent flows [61].

4.5. AI-Enhanced Sustainability Learning: Opportunities and Safeguards

Artificial intelligence (AI) offers significant potential to enhance inclusion and personalisation in sustainability education. Key opportunities include multilingual scaffolding (such as voice-to-text journaling), adaptive challenges aligned with developmental stages, and teacher planning tools linked to curriculum objectives and Sustainable Development Goal (SDG) targets [62,63]. These features can support diverse learners by tailoring content and providing accessible pathways to engagement. However, integration must remain developmentally appropriate and prioritise child safeguarding. To avoid cognitive overload, AI-driven tools should emphasise play-based inquiry and concrete representations rather than abstract metrics.
Recent advances in educational technology underscore the potential of AI-driven adaptivity to personalise sustainability learning pathways, offering dynamic task sequencing and formative feedback aligned with developmental stages. Adaptive algorithms can analyse learner interactions to adjust complexity, pacing, and modality, supporting differentiated instruction and reducing cognitive overload. Multilingual scaffolds now extend beyond translation to include culturally localised narratives and voice-based interaction, enhancing inclusivity for emergent bilinguals. Mobile learning innovations—such as augmented reality, gamified eco-challenges, and context-aware prompts—further enable experiential engagement with sustainability concepts. These developments align with global calls for equitable, personalised learning ecosystems and require robust privacy-by-design safeguards to protect children’s data.
Safeguarding children’s rights requires robust privacy-by-design protocols. Measures such as on-device processing, parental consent flows, and strict data minimisation are essential to comply with GDPR and the UK ICO Children’s Code [64,65]. Furthermore, AI should augment—not replace—teacher mediation. Embedding explainable AI mechanisms and teacher-facing dashboards can ensure transparency, enabling educators to interpret algorithmic decisions and mitigate risks of bias or opacity [61,62]. These safeguards promote ethical, culturally responsive, and pedagogically sound practices.
Despite these opportunities, practical challenges persist. First, transparency in automated decision-making is critical; opaque recommendations undermine teacher agency. Explainable AI and dashboards should therefore display the logic behind adaptive prompts [62]. Second, there is a risk of over-interpreting child-generated data, such as inferring socio-emotional traits from brief interactions, which may lead to biased or inaccurate conclusions [61]. Third, strict governance of sensitive data remains non-negotiable, requiring compliance with GDPR and ICO standards through privacy-preserving architectures [39,48]. Collectively, these considerations underscore that AI integration in early childhood education must operate within transparent, privacy-conscious, and developmentally appropriate frameworks.

4.6. Consolidated Design Implications

To address systemic gaps identified across app evaluations, the following consolidated design implications are proposed:
  • Broaden topic coverage beyond nature-centric content to include social/economic strands (e.g., fairness, sharing, community helpers, local markets) mapped to SDG 1, 2, 8, 10, 16, and 17 through play-based tasks and stories.
  • Accessibility and inclusion: implement WCAG 2.1 AA compliance, device-level text-to-speech, typographic scaling, high-contrast themes, and multilingual scaffolds (dual-language prompts, audio dubbing) to uphold equity.
  • Pedagogical alignment: replace text-heavy delivery with multimodal scaffolds (audio narration, icons, visuals with signalling/coherence principles), and embed child-facing SDG icons with plain-language descriptors.
  • Child agency and collaboration: provide documentation tools (journals, photo annotation, voice notes) and teacher-moderated dialogic prompts to foster inquiry, co-decision-making, and safe collaboration.
  • Mobile-first affordances: exploit mobility for context-aware eco-tasks (photo journaling, GPS-triggered challenges, accelerometer-mediated games) with privacy-by-design safeguards.
  • Assessment and teacher support: integrate formative assessment mechanisms (success criteria, hints, exemplars, reflective prompts) and teacher dashboards for planning, differentiation, and progress monitoring.
  • Ethical and privacy controls: enforce GDPR and ICO Children’s Code compliance through privacy by default, data minimisation, parental consent flows, and transparent retention policies [39,48].
  • Avoid dark patterns: audit freemium flows to eliminate manipulative design patterns (e.g., coercive upselling, reward gating) and ensure equitable classroom use.
Collectively, these measures align learn-on-the-move design with TSE by enabling progression from awareness to integration, and ultimately, to action, while safeguarding child agency and digital rights [14,15].

4.7. Implications and Recommendations

The implications and recommendations for developers are as follows:
  • Broaden SDG coverage beyond nature-only themes to include social and economic strands (SDGs 1, 10, 16, and 17).
  • Ensure WCAG 2.1 AA compliance and multilingual scaffolds to equity [31,36].
  • Integrate formative assessment (e.g., feedback, reflection prompts, success criteria) and teacher dashboards to support differentiated instruction [40].
  • Add community-linked challenges and co-creation features to foster action [14].
  • Apply privacy by design and comply with GDPR and the ICO Children’s Code for safeguarding [39,48].
  • Avoid manipulative design patterns (e.g., obfuscated subscription flows, coercive upselling, reward gating), maintain transparency in registration and data collection, and ensure platform parity to prevent OS-based exclusion in mixed-device ECE settings.
The implications and recommendations for educators are as follows:
  • Use documentation tools (e.g., journals, photo-annotation, voice notes) and dialogic prompts to support inquiry and agency [23,45].
  • Embed activities to local cultural contexts (e.g., folk stories, local festivals, family and community practices) for relevance and engagement [32].
  • Leverage dashboards for sustainability learning progress monitoring and cross-curricular integration.
The implications and recommendations for policymakers are as follows:
  • Mandate accessibility, teacher-facing supports, and interoperability in quality assurance frameworks.
  • Incentivise co-design with educators and families for cultural responsiveness.
  • Provide professional development for teachers on integrating digital sustainability tools.
The implications and recommendations for operationalising cultural responsiveness are as follows:
  • Include multilingual scaffolds (dual-language prompts, home-language audio).
  • Localise examples (community practices, cultural events) and provide teacher-side editing tools.
  • Represent diversity through avatars and narratives.
  • Offer offline-first audio and icon packs for low-bandwidth contexts.
  • Align with experiential learning and SDG 4.7 to ensure relevance and engagement.
Illustrative examples for cultural responsiveness are as follows:
  • Social sustainability:
    • Interactive story modules simulating resource-sharing during a drought (SDG 6, SDG 10).
    • Digital eco-journals for recording acts of kindness (SDG 16).
    • Avatar-based community clean-up challenges featuring diverse families (SDG 4.7, SDG 10).
2.
Economic sustainability:
  • Gamified “pretend shop” for trading recycled items (SDG 12, SDG 8).
  • Drag-and-drop budgeting games for classroom resources (SDG 1, SDG 8).
  • Categorisation mini-games distinguishing “needs” vs “wants” (SDG 12).

4.8. Limitations and Future Research

This study presents several limitations that shape the interpretation and generalisability of its findings. First, the sample was restricted to English-language and free or freemium applications. While this criterion aligns with equity principles for resource-constrained contexts [36], it excludes paid and non-English apps that often incorporate advanced features such as multilingual scaffolds, culturally localised content, and teacher dashboards. These omissions may under-represent design innovations prevalent in international markets and limit insights into culturally responsive sustainability learning [32,35].
Second, the artefact-based approach adopted here ensured compliance with UNCRC Article 12 by avoiding direct child participation and safeguarding children’s rights [37,38]. However, this design limits ecological validity because app use was not observed in authentic classroom settings. Without classroom trials, it remains unclear whether identified design gaps, such as accessibility and agency affordances, translate into practical barriers or adoption challenges. Future research should incorporate classroom-based trials and participatory design-based research to capture teacher mediation, peer collaboration, and child agency, which are central to transformative sustainability education [13,60]. Longitudinal studies could further assess whether app features support sustained engagement and experiential learning outcomes [26,45].
Third, the historical evolution of apps was not examined in depth. Tracking release dates, update cycles, and feature modifications could reveal whether apps are adapting to accessibility standards and pedagogical expectations over time. Future work should integrate this historical lens and link design changes to measurable learning outcomes through empirical studies on mobile learning effectiveness [10,11].
Collectively, these directions will strengthen methodological rigour, cultural responsiveness, and practical impact, advancing the field of early childhood sustainability education.

5. Conclusions

This review highlights a critical gap in early childhood sustainability apps: most remain environmentally narrow, lack inclusive design, and provide minimal teacher support. Moving forward, development should prioritise balanced SDG coverage, accessibility compliance, and teacher-facing tools to ensure equity and adoption. Emerging technologies such as AI-driven adaptivity, multilingual scaffolds with culturally localised narratives, and augmented reality affordances offer pathways to personalised, situated sustainability learning. These innovations must be implemented within privacy-by-design and teacher-mediated frameworks to ensure developmental appropriateness. Future research should shift from artefact analysis to classroom trials, co-design with educators, and longitudinal studies to evaluate transformative learning outcomes. In addition, it should examine how AI-driven adaptivity, multilingual scaffolds, and emerging mobile learning affordances, such as AR and gamification, can be integrated into early childhood sustainability education to enhance engagement and equity. This study extends prior mobile learning evaluations by embedding accessibility, cultural responsiveness, and interdisciplinary integration into a dual-framework rubric, addressing gaps in existing models that focus narrowly on usability or pedagogy. These contributions advance transformative sustainability education by operationalising SDG 4.7 principles in early childhood contexts.
This study contributes theoretically, empirically, and practically to early childhood sustainability education. Theoretically, it advances mobile learning evaluation by integrating pedagogical, accessibility, and cultural responsiveness dimensions into a dual-framework rubric. Empirically, it provides a systematic artefact-based review of 11 apps, supported by high inter-rater reliability, revealing systemic gaps that limit transformative learning. Practically, it offers actionable design implications, such as WCAG compliance, multilingual scaffolds, and teacher dashboards, that align with global equity and child rights principles, informing developers, educators, and policymakers. Despite iterative updates, most apps show limited progress toward WCAG compliance and culturally grounded design, underscoring the need for regulatory and pedagogical alignment in future development. Implementing these design principles can inform global quality assurance standards, guide developers toward inclusive practices, and support policymakers in embedding sustainability learning within early childhood curricula.

Author Contributions

Conceptualisation, S.C.N. and K.L.C.H.; methodology, S.C.N., C.M.T., and M.F.L.; software, S.N.C. and Y.H.L.; validation, C.M.T. and M.F.L.; formal analysis, S.N.C. and Y.H.L.; investigation, S.N.C. and Y.H.L.; resources, S.N.C. and Y.H.L.; writing—original draft preparation, S.N.C., Y.H.L., and K.L.C.H.; writing—review and editing, K.L.C.H., S.C.N., C.M.T., and M.F.L.; supervision, S.C.N. and K.L.C.H.; project administration, K.L.C.H.; internal funding acquisition, K.L.C.H. All authors have read and agreed to the published version of the manuscript.

Funding

This research received no external funding.

Institutional Review Board Statement

Not applicable for studies not involving humans or animals.

Informed Consent Statement

Not applicable for studies not involving humans or animals.

Data Availability Statement

The original contributions presented in this study are included in the article. Further inquiries can be directed to the corresponding author.

Acknowledgments

This work was supported in part by Anglia Ruskin University (ARU) through the Arts, Humanities, Education and Social Sciences (AHESS) Impact Funding for the project Empowering sustainability literacy: Creating a ChatGPT-driven mobile app for early childhood sustainability lesson planning. The authors would like to thank our research staff, Siu Nam Chan, and Yat Him Lee for their contributions to the project. During the preparation of this manuscript/study, the authors used Grammarly for the purposes of proofreading. The authors have reviewed and edited the output and take full responsibility for the content of this publication.

Conflicts of Interest

The authors declare no conflicts of interest.

Appendix A. Codebook Extract: Rubric Criteria and Indicators

Table A1. Rubric criteria and indicators.
Table A1. Rubric criteria and indicators.
CriterionDefinitionECE FrameworksIndicators (Score Anchors)
Learn on the moveExtent to which the app enables mobile-specific, context-aware learning beyond static screen interaction.Experiential learning cycle; EYLF play in context [23,28,45]1: no mobile affordances; 3: basic mobility (e.g., unlock stages); 5: context-aware tasks (GPS/photo journaling) with privacy safeguards.
User role and profileDegree of role differentiation and personalisation for learners and educators.Adult mediation; teacher scaffolds; DAP [23,32]1: single generic role; 3: participant role with minimal profile; 5: multiple roles (learner/teacher), customisable profiles, privacy by design.
Interface designUsability and accessibility of navigation, layout, and controls.Multimodal scaffolds; cognitive load reduction [44,66]1: dense text, poor wayfinding; 3: clear menus, basic WCAG compliance; 5: child-friendly UI (large tap targets, progressive disclosure, full WCAG 2.1 AA).
Media typesVariety and pedagogical appropriateness of media used for content delivery. 1: text only; 3: text + static images; 5: multimodal (audio, video, interactive graphics) aligned with multimedia learning principles.
Collaboration
support		Opportunities for dialogic interaction and co-creation among learners and teachers.Dialogic interaction; co-creation [23]1: none; 3: broadcast feeds or emoji reactions; 5: teacher-moderated shared artefacts, commenting with prompts, consent-aware sharing.
Integration of toolsPresence of capture tools, analytics, and interoperability features. 1: no integration; 3: basic capture (photo/audio); 5: full integration (journals, dashboards, offline-first, export options).
Pedagogical approachAlignment with inquiry-based, play-based, and dialogic learning principles.Inquiry/play-based sequences (Siraj-Blatchford; Kolb) [13,45]1: information delivery only; 3: quiz-based or gamified tasks; 5: inquiry/play-based sequences with reflective prompts and interdisciplinary links.
Assessment techniquesDepth and formative value of assessment features.Formative feedback; success criteria [39,40]1: none; 3: summative scoring or leaderboards; 5: formative feedback, journalling, success criteria, teacher dashboard.
Teacher-facing supports/CPDFeatures that assist educators in planning, monitoring, and professional learning.Planning templates; differentiation [40]
1: none; 3: basic progress view; 5: planning templates, analytics, CPD prompts, exportable reports.
AccessibilityCompliance with inclusive design standards and multilingual scaffolds.WCAG/UDL for ECE; multilingual scaffolds [30,31,32]1: no accessibility features; 3: partial WCAG compliance (font scaling only); 5: full WCAG 2.1 AA + multilingual support + TTS/audio captions.
Scoring Notes. Ratings are ordinal (1–5); adjacent points do not imply equal intervals. Anchors represent behavioural indicators observed during app review. Privacy and safeguarding requirements follow GDPR [39] and ICO Children’s Code [48]. Accessibility benchmarks align with WCAG 2.1 Level AA [31].

Appendix B. Worked Example of Scoring Process

To enhance transparency and reproducibility, Table A2 illustrates the scoring process for ECE Academy—Sustainability, which achieved the highest overall rating in our sample. Each criterion is shown with its ordinal score (1–5) and a brief rationale aligned to the rubric anchors.
Table A2. Example of rubric application for ECE Academy—Sustainability.
Table A2. Example of rubric application for ECE Academy—Sustainability.
CriterionScoreRationale
Learn on the move4Includes context-aware prompts and offline journaling but lacks GPS triggers
User role and profile5Provides differentiated roles (teacher/learner) and privacy-by-design profiles
Interface design4Child-friendly UI with large tap targets; partial WCAG compliance
Media types4Multimodal (text, audio, images) aligned with multimedia learning principles
Collaboration support3Offers teacher-moderated journaling but no synchronous co-creation tools
Integration of tools5Includes journaling, photo annotation, and export options
Pedagogical approach5Inquiry-based sequences with reflective prompts and interdisciplinary links
Assessment techniques5Formative feedback, journaling, and teacher dashboard
Teacher-facing supports/CPD4Planning templates and analytics; lacks embedded CPD micro-modules
Accessibility3Partial WCAG compliance; no multilingual scaffolds
This example demonstrates how ordinal anchors guided scoring decisions and how interpretive complexity was addressed through explicit rationale. Providing such exemplars supports methodological transparency and facilitates replication in future studies [51,52].

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Table 1. Apps reviewed in this study.
Table 1. Apps reviewed in this study.
App Name
1. The Planet App7. Endless Learning Academy
2. Environment Quiz8. WWF Together
3. Environmental Studies9. ECE Academy—Sustainability
4. Environmental Studies Notes10. Earth Hero: Climate Change
5. Carbon Cutting Essex11. LGBT Flags Merge!
6. Klima—Fight Climate Change
Table 2. The languages which are used in at least 2 reviewed apps.
Table 2. The languages which are used in at least 2 reviewed apps.
LanguageApp(s) That Use That Language
ChineseWWF Together (App 8)
Earth Hero: Climate Change (App 10)
LGBT Flags Merge! (App 11)
FrenchEnvironment Quiz (App 2)
WWF Together (App 8)
Earth Hero: Climate Change (App 10)
LGBT Flags Merge! (App 11)
GermanKlima—Fight Climate Change (App 6)
Earth Hero: Climate Change (App 10)
LGBT Flags Merge! (App 11)
JapaneseEarth Hero: Climate Change (App 10)
LGBT Flags Merge! (App 11)
SpanishThe Planet App (App 1)
WWF Together (App 8)
Earth Hero: Climate Change (App 10)
LGBT Flags Merge! (App 11)
Table 3. The platform(s) that is/are available for the reviewed apps.
Table 3. The platform(s) that is/are available for the reviewed apps.
Platform(s)App(s) That Are Available in
App Store onlyEndless Learning Academy (App 7)
WWF Together (App 8)
Google Play onlyEnvironment Quiz (App 2)
Environmental Studies (App 3)
Environmental Studies Notes (App 4)
App Store and Google PlayThe Planet App (App 1)
Carbon Cutting Essex (App 5)
Klima—fight climate change (App 6)
ECE Academy—Sustainability (App 9)
Earth Hero: Climate Change (App 10)
LGBT Flags Merge! (App 11)
Table 4. The criteria included in the comparison.
Table 4. The criteria included in the comparison.
Target UserSDG(s) IncludedAccessibility
Ease of useLanguageCharacteristics
PlatformPriceTopic
Media typeIntegration of toolsPedagogical approach
Assessment techniquesTeacher learningLearn on the move
User role and profileInterface designCollaboration support
Interdisciplinary
Table 5. SDG coverage by app (coded for operationalisation in interactive tasks).
Table 5. SDG coverage by app (coded for operationalisation in interactive tasks).
App/SDG1234567891011121314151617
1. The Planet App x x x
2. Environment Quizx x x x x x x x x x x x x x xx x
3. Environmental Studies x x x
4. Environmental Studies Notes xxx x
5. Carbon Cutting Essex x x x
6. Klima—Fight Climate Change x x
7. Endless Learning Academy
8. WWF Together x x x x
9. ECE Academy—Sustainabilityx x x x x x xx x x xx x x
10. Earth Hero: Climate Change x x x x x
11. LGBT Flags Merge! x x
Table 6. The integration of tools of each app.
Table 6. The integration of tools of each app.
Platform(s)App(s) Related to That Approach
Supportive toolThe Planet App (App 1)
ECE Academy—Sustainability (App 9)
Earth Hero: Climate Change (App 10)
Instructional toolEnvironment Quiz (App 2)
Endless Learning Academy (App 7)
WWF Together (App 8)
None of the aboveEnvironmental Studies (App 3)
Environmental Studies Notes (App 4)
Carbon Cutting Essex (App 5)
Klima—Fight Climate Change (App 6)
LGBT Flags Merge! (App 11)
Table 7. The pedagogical approaches of each app.
Table 7. The pedagogical approaches of each app.
Approach(es)App(s) Related to That Approach
ConstructivismEnvironment Quiz (App 2)
Environmental Studies (App 3)
Environmental Studies Notes (App 4)
Endless Learning Academy (App 7)
WWF Together (App 8)
ECE Academy—Sustainability (App 9)
LGBT Flags Merge! (App 11)
Blended learningN/A
Collaborative learningThe Planet App (App 1)
Active learningEarth Hero: Climate Change (App 10)
None of the aboveCarbon Cutting Essex (App 5)
Klima—Fight Climate Change (App 6)
Table 8. Completed assessment techniques table.
Table 8. Completed assessment techniques table.
App NameAssessment Technique
The Planet App (App 1)Action pledges and ranking
Environment Quiz (App 2)Score-based progression
Environmental Studies (App 3)Static content, no assessment
Environmental Studies Notes (App 4)Static content, no assessment
Carbon Cutting Essex (App 5)Points and leaderboard
Klima—Fight Climate Change (App 6)Carbon footprint calculator
Endless Learning Academy (App 7)Unlockable stages
WWF Together (App 8)None
ECE Academy—Sustainability (App 9)Formative feedback, journaling, teacher dashboard
Earth Hero: Climate Change (App 10)Carbon tracking and goal setting
LGBT Flags Merge! (App 11)None
Table 9. The assessment techniques of each app.
Table 9. The assessment techniques of each app.
AppComputer-BasedSelf-AssessmentPeer Assessment
The Planet App (App 1)YesYesYes
Environment Quiz (App 2) Yes
Carbon Cutting Essex (App 5)Yes
Klima—Fight Climate Change (App 6)Yes
Endless Learning Academy (App 7)YesYes
ECE Academy—Sustainability (App 9)YesYes
Earth Hero: Climate Change (App 10)YesYesYes
Table 10. Suitability of the reviewed app for sustainability learning.
Table 10. Suitability of the reviewed app for sustainability learning.
SuitabilityFor Sustainability Learning
YesThe Planet App (App 1)
Environment Quiz (App 2)
Environmental Studies (App 3)
Environmental Studies Notes (App 4)
Carbon Cutting Essex (App 5)
Klima—Fight Climate Change (App 6)
WWF Together (App 8)
ECE Academy—Sustainability (App 9)
Earth Hero: Climate Change (App 10)
LGBT Flags Merge! (App 11)
NoEndless Learning Academy (App 7)
Table 11. Examples of rubric mapping by app (pedagogical approach; assessment technique).
Table 11. Examples of rubric mapping by app (pedagogical approach; assessment technique).
App NamePedagogical ApproachAssessment Technique
ECE Academy—Sustainability (App 9)Inquiry-based, reflective prompts, interdisciplinary linksFormative feedback, journaling, teacher dashboard
Environment Quiz (App 2)Quiz-based, factual recallScore-based progression
Endless Learning Academy (App 7)Play-based, multimedia learningUnlockable stages
Carbon Cutting Essex (App 5)Action-based pledges, gamified rankingPoints and leaderboard
WWF Together (App 8)Visual storytellingNone
Table 12. Inter-rater reliability by criterion (weighted κ).
Table 12. Inter-rater reliability by criterion (weighted κ).
CriterionCohen’s Kappa
Learn on the move1.00
User role and profile0.74
Interface design1.00
Media types1.00
Collaboration support1.00
Integration of tools1.00
Pedagogical approach0.87
Assessment techniques0.88
Teacher learning0.88
Accessibility1.00
Overall, κ values indicate substantial to almost-perfect agreement.
Table 13. App-level summary.
Table 13. App-level summary.
App NameTotal ScoreSDG CoverageAccessibilityTarget Age GroupOverall Rating
ECE Academy—Sustainability (App 9)451, 2, 4, 5, 8, 9, 10, 11, 12, 13, 14, 15, 16, 173ECE educators and parentsHigh
Environment Quiz (App 2)30All 17 SDGs2Kids and adultsMedium
Endless Learning Academy (App 7)33None2Preschool to Grade 1Medium
Carbon Cutting Essex (App 5)3212,13,152General publicMedium
WWF Together (App 8)207, 12, 14, 151General publicLow
Earth Hero: Climate Change (App 10)304, 11, 12, 13, 172General publicMedium
Environmental Studies (App 3)237, 12, 131General publicLow
Environmental Studies Notes (App 4)2312, 13, 14, 151General publicLow
Klima—Fight Climate Change (App 6)2412, 131General publicLow
The Planet App (App 1)3812, 13, 152General publicMedium
(LGBT Flags Merge! is not listed in the above table). Accessibility reflects presence of WCAG-aligned features (e.g., TTS, font scaling, contrast, captions); mean rounded to nearest integer.
Table 14. Release history and major updates of the reviewed apps.
Table 14. Release history and major updates of the reviewed apps.
App NameRelease YearLast UpdateMajor Changes
1. The Planet App2020Sep 2024Removed from Google Play since 15th September 2025
2. Environment Quiz2020Aug 2024Brand new, clean app using last performance libraries since August 2024 (last update)
3. Environmental Studies2019Apr 2025Minor bug fixes and improvements
4. Environmental Studies Notes2018Sep 2025More interactive and engaging content
5. Carbon Cutting Essex2023Aug 2025App refreshed, bug fixed, push notifications improved
6. Klima—Fight Climate Change2020Aug 2024Removed from Google Play since 1st May 2025
7. Endless Learning Academy2015Apr 2025Different themed content packs were included (e.g., Winter, Halloween, Summer, Valentine’s Day)
8. WWF Together2013Feb 2021New species added to the interactive 3D globe, app size reduced, new animal stories after voting
9. ECE Academy—Sustainability2023Feb 2025Different languages were added (e.g., Spanish, Czech, Slovak, Croatian) and fixed missed translation
10. Earth Hero: Climate Change2019Nov 2025New actions, languages, and climate groups are added
11. LGBT Flags Merge!2020Mar 2025New flags added, multiple languages for the tutorial
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Ng, S.C.; Ho, K.L.C.; Tang, C.M.; Leung, M.F.; Lee, Y.H.; Chan, S.N. Assessing Early Childhood Sustainability Apps: A Dual-Framework Evaluation. Sustainability 2026, 18, 299. https://doi.org/10.3390/su18010299

AMA Style

Ng SC, Ho KLC, Tang CM, Leung MF, Lee YH, Chan SN. Assessing Early Childhood Sustainability Apps: A Dual-Framework Evaluation. Sustainability. 2026; 18(1):299. https://doi.org/10.3390/su18010299

Chicago/Turabian Style

Ng, Sin Chun, Ka Lee Carrie Ho, Chung Man Tang, Man Fai Leung, Yat Him Lee, and Siu Nam Chan. 2026. "Assessing Early Childhood Sustainability Apps: A Dual-Framework Evaluation" Sustainability 18, no. 1: 299. https://doi.org/10.3390/su18010299

APA Style

Ng, S. C., Ho, K. L. C., Tang, C. M., Leung, M. F., Lee, Y. H., & Chan, S. N. (2026). Assessing Early Childhood Sustainability Apps: A Dual-Framework Evaluation. Sustainability, 18(1), 299. https://doi.org/10.3390/su18010299

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