This is kind of an "un-review". I have a product I am looking for and having trouble finding. I need an app that works with the top fitness trackers (fitbit, Garmin, Nike), preferably is android and Apple compatible, and supports group challenges. There can be a fee for the group organizer but not for the users. I would really appreciate any suggestions people might have, even if you're not sure it meets all the criteria. I am making a list and have some people to go through and vet each of the possibilities.