Android devices are notoriously rubbish with applications utilising their directional sensors (magnetometers), its actually quite well documented on the world wide wonder web.
You will probably fine that most of the time your Inspire graphic in the corner is around 45degrees out from the direction it should be. Sometimes less, sometimes more. Unfortunately there is not an awful lot that can be done to rectify the problem.
The important thing to watch out for is the Inspires orientation on the map screen should be correct in relation to the overlay/satellite's image data. If it is not, do not take off!
Power down your aircraft,reposition of and try again.
Hope that helps.