Very inaccurate

Found it to be very inaccurate and virtually impossible to calibrate. It gives me a different heading every time I use it from exactly the same location. It is even worse now with iOS-7. So frustrating I am removing it and using the one that came pre-installed on my iPhone which is very accurate and calibrates easily every time.

ChiefEngRtd. about Commander Compass Go, v3.3.9