I wonder if there could be a solution for this that doesn't require an app... my use case for this is being underground on the tube (I live in London) on the way to a class/social, wanting to check my moves and decide what to focus on. Or perhaps after a class on the way home, to add notes or consider how I got on, or to add new moves from class videos(though I imagine that part would be much harder offline and is less important)