my friend Nik and I have been talking about making a FLOSS training app. There's probably a small market for something like Fitbit or Garmin Connect that is privacy-focused, but my guess is you would need to have connections to "elites".

Anyway, we have a GitHub organization, but no code yet.

Nik is obsessed with starting a business, but I don't think he's a very good developer. Still, he continues to learn, so he might get there.

Anyway, I could send you his email if you would be interested in speaking with him about his various business ideas.