Active play in a digital age: exploring children's views of a physical activity app. (Preprint)

BACKGROUND The use of smartphones and interest in mobile health (mHealth) has grown in recent years with physical activity apps demonstrating potential to facilitate behaviour change. However, there remains limited understanding of what specifically motivates children to engage meaningfully with these tools. OBJECTIVE This qualitative formative study aimed to determine children's perceptions of a bespoke physical activity app (Bestlife). It sought to explore the app’s appeal, functionality, and potential to support behaviour change among children aged 8–13. METHODS Citizen scientists (n=68) were asked to download and explore the Bestlife app 1- 2 weeks before the research session, completing a booklet to capture their and their families experiences. Thirteen focus groups were conducted across five schools to explore children's views in depth. The focus groups were designed to investigate children's perceptions of the app. Qualitative data were analysed inductively and deductively: An initial inductive analysis identified emerging themes, which were then mapped onto a framework of feasibility, usability, acceptability, and behaviour change. RESULTS The study identified key factors influencing the feasibility, acceptability, usability, and behaviour change potential of the Bestlife app among children. Feasibility was hindered by the parental email requirement during registration, which limited autonomy for older children. Acceptability was driven by gamified features, proportional rewards, and avatar customisation, though participants requested more personalisation to promote cultural inclusion and dynamic updates, linked to seasonal themes. Usability findings showed the interface was intuitive, with features promoting social interaction and competition enhancing engagement. However, younger users experienced navigational challenges, underscoring the need for clearer guidance. The app effectively incorporated behaviour change techniques, including goal-setting, self-monitoring, and social collaboration, but required adjustments, such as reducing the frequency of emotional tracking prompts. CONCLUSIONS The Bestlife app shows potential as an mHealth intervention for promoting physical activity in children. Enhancing cultural representation, simplifying onboarding processes, and refining engagement strategies could strengthen both uptake and sustained use. These findings highlight the importance of integrating user feedback into the iterative design process to optimise digital health tools for young populations. Further longitudinal research is recommended to evaluate longer term engagement with the app's it’s impact on physical activity levels, and behaviour change sustainability.