@Suty sorry, but adding a calibrate button that offsets whatever value the device is returning by the module of this angle plus the set offset doesn't seem to be too difficult, and fixes this annoyance of the users rotting the cellphone to figure out if the storm is coming from behind you or from somewhere else in an unfamiliar region when you are travelling. Just adding my 2 cents. Cheers.

@Suty sorry, but adding a calibrate button that offsets whatever value the device is returning by the module of this angle plus the set offset doesn't seem to be too difficult, and fixes this annoyance of the users rotting the cellphone to figure out if the storm is coming from behind you or from somewhere else in an unfamiliar region when you are travelling. Just adding my 2 cents. Cheers.