Earlier quoted context omitted.
My wife bought me a new fitbit for Christmas (mine is getting old, frequently just loses it's charge, etc). It would not allow me to initialize it without syncing to my phone, which had to be running their app. I wound up returning it because I don't _want_ to run their app on my phone. I even looked into if it might be possible to work around the issue. Turns out, the fitbit, which is advertised as having a GPS, act…
Unfortunately that's the price you pay to use most devices - they need accompanying proprietary software. There doesn't seem to be a big enough market for open-standard or open-protocol health/fitness tracking.
It doesn't _need_ the phone to be able to do that part of it's job. And I don't want the "challenge your friends to a walk-a-thon" junk that does use the app.