Comment by nativeforks

> but I wonder how accurate the compass is

MBCompass uses sensor fusion for accuracy, combining sensor data from the accelerometer, gyroscope, and magnetometer.

It is one of the most accurate compass apps. Don't trust my words, try it with different apps on Google Play and with some FOSS options like Compass by Philip Bobek: https://f-droid.org/en/packages/com.bobek.compass

And importantly, for true compass accuracy, I'd recommend you use the "true north" (magnetic declination) function, which requires location access. It takes some time to lock GNSS hold (the same goes for the current location button on the map view, default map location is Paris, France), but if you're moving, it locks pretty quickly and shows your current location with tracking (if you're moving.)