If your phone runs on Android 5.0 Lollipop API level 21 or higher, it is compatible with the latest versions.
Older Android phones can still use Sports Tracker but updates or bug fixes are not available.
There may also be issues with synching to our service.
If you have issue with Google Play please check the following Google Play FAQ for help

Sports Tracker is optimised for "pure" Android. 

If you are using customised Android based operating systems there may occur compatibility issues with Sports Tracker app. e.g. 
Oneplus phones are using Customised Android called Oxygen OS.
Meizu phones are using Customised Android called Flyme OS.
Oppo phones are using Customised Android called  Color OS.