GMC's Google built-in infotainment runs Android Automotive OS across its truck and SUV lineup. AltitudeTracker works on 5 GMC models — the inclinometer and altitude tracking are especially useful for off-road and mountain terrain.
On your GMC's center display, open the Google Play Store from the apps screen.
Type "AltitudeTracker" or "altitude tracker" in the search bar.
Tap install, then open. No account needed — the app runs natively on your display.