May I suggest a new feature that I don't see in the fitness apps i've checked out. I listen to a lot of athletes on podcasts (JRE) and they always talk about proper form and its importance for taking care of your body. In things like yoga you could be damaging to your joints, spine, or muscles. Maybe have "exercise tips" or "learn how" section/videos. I know some exercises are intuitive and may not need this. Just throwing ideas.