not any good ones that I found. At least compared to Strava/Training Peaks, which is what I use now.
Discussion
Fair enough. I know Gadgetbridge lets you use some existing devices, but seems to lack in functionality and device coverage.
yeah it's pretty much all the off brand devices. anything worthwhile (imo) is not going to allow for that functionality. maybe one day. I do prefer garmin because they at least say they don't sell your personal data. Still collecting it, of course.