Hi @Camaleon, I don't have answers for your questions but it seems you're trying to build something that already exists - I’m using the RunGap app that actually does this (it's for iOS only though, other similar apps are here). I'm mentioning this just in case it could save you some headache, but of course you might want some specific design - hopefully someone will be able to provide those answers 
For the second part about the Strava API: The usage is free, but you get enforced personal limits how many athletes can connect and how many requests you can make per 15 min and per day.
With Health Sync, available on both iOS and Android you can sync to Apple Health and to Health Connect. See https://healthsync.app for details. Cheap and easy to use.
Thanks jana_s, Jan_Mantau and hophoff.
About rungap and healthsync. Not working for my needs. Let me explain some details. i plan an app which will be free for most users. But jace some needs to be complete:
- Need to work with IOS amd Android (RunGap works Ios).
- I want to resume all activities from as many apps as possible.
- My app is not proper a sport companion, neither a syncer. My app gets all the info to analyze.
- Need to have an open API that is free so I could connect my app to read the total data.
O know is complex. But not having it means to me reading 1 by 1 apis, that could be changing and some may cost and my app will be free, so no way. That is why if all could send to HealthConnect and HealthKit will be free and just 1 types. But open to any other options.
Jan_mantau, as I read in other places. Strava may charge even if is few athlets if is production. Is there any reference of pricing?
If is very cheap (example $20/month or 1 time price) then is no problem. But if it could be hundreds per month is not my option.
That is why I prefer connecting to a Free hub as HealthConnect or HealthKit.
To my knowledge Strava does not charge for API usage, at least within reasonable limits.
Hello @Camaleon,
The Strava REST API includes data on athletes, segments, routes, clubs, and gear. It is free to use.
Check out this support article on the Google Fit integration which may address some of the roadblocks you’re facing when trying to set up your testing.
@Emily_A Thanks.
I follow about Google Fit, but is very strange. Months ago seems Strava send info to Google Health and apears to Google Fit. But now something happend and stop apearing. I follow the article and everything was OK, but the same result.