Fig. 1

Application of the IDEAS framework to the development of Vegethon mobile app. Empathize: gather qualitative insights from users (e.g., in-depth interviews, focus groups). Specify: translate broad behavioural goals into a highly specific target behaviour, taking into consideration actionability, health impact, and user acceptability. Ground: ground intervention in behavioural theory and evidence and incorporate relevant behavioral strategies. Ideate: brainstorm creative strategies for translating theory and user insights into features, using inspiration from wide and varied sources. Prototype: develop rough prototypes of ideas rapidly and iteratively, sharing, discussing, and improving prototypes as a cross-sector team. Gather: gather user feedback on prototypes (e.g., interviews, questionnaires), and uncover insights to inform product improvement. Build: build a fully functional minimum viable product, and incorporate app analytics to collect data on app usage patterns. Pilot: conduct a small-scale evaluation of the intervention to test potential efficacy, feasibility, and usability, analyze usage behaviour, and refine study protocol