Reference frame for motion
It appears that the default reference frame used by pythonista when calling core motion is either xarbitrary, or xarbitrary with magnetometer stabilization... Not sure which.
As a suggestion for future versions, would it be possible to specify which frame to use? And, to provide access to the magnetometer estimated accuracy value, and the ability to pop up that thingie to calibrate the compass?
I was working on a simple compass app, (using get_attitude, since the magnetometer readings don't seem to work) and finally figured out that the initial heading always starts out at 0.