Over a few weeks, I observed how he tracked my progress on the tablet with spreadsheets.
That included goals, exercise history, and measurements. We took short videos of proper techniques.
The idea of the app was obvious. Each trainer should be able to create a program, post videos, keep track of the client's progress, and make money. Training buddies should be able to share their progress and schedules. The app creation process was a great motivation to stay fit, too!