Co‐designing a just‐in‐time adaptive mHealth intervention to improve parental support for child physical activity using a no‐code app design platform: Development study

Parental support significantly influences children's physical activity (PA) levels. Just‐in‐time adaptive interventions (JITAIs) delivered through mobile health (mHealth) may provide personalized, dynamic support to parents, though research is limited. 1) Describe the co‐design process of a family‐based JITAI app designed to help parents support their children's PA, and 2) evaluate the resources required to co‐design this app using a “no‐code” platform, Pathverse. Following the Integrate, Design, Assess, Share (IDEAS) and Multi‐Process Action Control (M‐PAC) frameworks, parents of children 8–12 years not meeting PA guidelines participated in semi‐structured interviews (Phase 1). Feedback‐informed app features, JITAI tailoring strategies, and prototype refinement (Phase 2). Six parents participated in Phase 1 guided by the IDEAS framework, with parental feedback directly shaping the app design. Parents emphasized family‐based content, gamification, and diverse PA activities, while barriers (e.g., time, weather) informed JITAI tailoring. The M‐PAC framework guided the selection and delivery of behavior change techniques (e.g., self‐monitoring, social support). Development required 320 hours over four months, including decision‐tree creation (50), uploading dynamic content (70), and testing (80). A family‐based JITAI app was co‐designed leveraging the M‐PAC framework and Pathverse to integrate parental support for PA, laying the groundwork for future testing.