What is the exact symptom? It might be more than just an app issue. Have you ever tried rebooting the IHU and TCAM?
Some hidden functions:
Home button: (the rectangular button immediately below the center infotainment screen)
- Press and hold for ~20 seconds to reboot the infotainment system (IHU).
Front windshield defrost button:
- Press and hold for ~20 seconds to reboot the TCAM unit. (LTE / GPS / WiFi / etc)
- YMMV (some owners claim that this didn't work for them, but it does for many)
Media Play/Pause button: (the round button in the center of the rotary volume control)
- Press and hold for ~5 seconds to turn the vehicle off without having to leave.