Table 1.

Case study framework (based on [24,25]).

Number	Stage	Corresponding agile stage	Outcomes
1	Plan	Discovery phase	Description of problem, user journeys, and data aggregation approach
2	Design	Alpha phase	Construction of research design and linkage of research questions, data, and criteria for evaluation and synthesis Development and design of app prototype based on the behavior change wheel theoretical framework [20], which will be iteratively updated based on new incoming evidence from steps 4 and 5
3	Prepare	Alpha phase	Drafting, approval, and execution of study ethics followed by the performance of user recruitment protocols Design of short-term and long-term app evaluation protocols
4	Collect	Beta phase	Deployment of a beta version of the app and conduction of qualitative semistructured interviews and in-app surveys, and collection of app use data.
5	Analyze	Beta phase	Iterative user data analysis for continuous app improvement
6	Create	Live phase	Finalize app for publishing on Google and Apple app stores
7	Share	Live phase	Ongoing paid advertising to promote uptake of the app Creation of interim and long-term reports based on iteratively collected data and a final report of the impact of the app on reducing social isolation, improving well-being, and providing useful tracking data Publishing of the reports in a peer-reviewed journal.