If you have considered wearing a smartwatch but were afraid of how your personal / vital data gets handled there might be a solution. On F-Droid there is Gadgetbridge: An app for Android that connects to your smartwatch/Fitnesstracker and analyzes your vital data without using the manufacturers proprietary app or sending it to any other place. Gadgetbridge stores all the data from the watch solely on your phone and works even without internet connection. It tracks your activity and sleep and sends phone notifications to your watch.
Gadgetbridge works with a bunch of smartwatches, please check out the website for the current status as they’re adding support for more devices over time.
I personally have used Gadgetbridge with 2 devices so far:
Both of them worked pretty much flawlessly with gadgetbridge but the Pebble2 is not available anymore (Pebble has been bought by Fitbit). The Amazfit BIP is manufactured by Xiaomi and is still available.
Amazfit BIP
To be honest: I am surprised about several things of the BIP. Firstly it’s pretty cheap. On several Internet shops it costs about 70 EUR.
Secondly it has a great design (comparable to an Apple Watch) but is much lighter than the Apple Watch. Wearing the BIP makes you nearly forget you are wearing a wristwatch packed with a ton of features.
Third: its packed with a ton of Features 😉 different watchfaces, a heartratemonitor, notifications from your smartphone, weather status, a step- and caloriecounter and even a GPS-Tracker. The heartrate sensor seems to deliver expected results, but the GPS Sensor doesn’t really work reliable all the time. Even after a few firmware updates from the manufacturer directly it still “jumps” while tracking my run. So if you’re dependent on good GPS-Data this watch mighr not be suitable for you.
Best of all: Battery life of 7-10 days in constant use ! Wow ! not even the Pebble had this battery life. Even with using GPS every second day for an hour it is still working 5-7 days without charging. And if you are not wearing the watch it won’t drain battery at all (or at least not remarkably 😉
So overall i can recommend wearing this watch in combination with Gadgetbridge if you want your privacy being respected.
Addition 2020/12/15
The GPS reliability is fine now (after several firmware upgrades) but there seems to be another issue with using it during workouts: the workout mode has no lock-feature. So if you’re wearing long sleeves (like me during running in winter time) they are taken as finger swipes and might change the settings. In many times it even cancelled the workout 🙁 The Amazfit support said, after being asked, that locking the watch during activity is not supported at the moment. Sad but true 🙁