I think the app would be more sticky, if the clients got monthy, weekly, yearly insights and reviews. For exmaple Oura ring gives a weekly review and insights on heart rate, step count etc. I think because of the data collected it should be that hard to give an average steps, steps goals hit, average weight, flucuations, pr's hit, etc weekly. I also think a year in review much like how spotifiy does their year wrapped would allow the app to be more sticky and clients would look forward to their year wrapped.