I'm developing an app that uses CMMotionManager, and prior iOS 10, the data from manager was stable. After iOS 10 update it started 'jumping' (data for the moment t+1 is times bigger than data for moment t, and at moment t+2 it returns to stable state). I'm using attitude property of CMDeviceMotion, and reference frame CMAttitudeReferenceFrameXTrueNorthZVertical.
What can I do to stabilize data from Manager?
This is entirely an iOS 10 bug. Unfortunately apple does not even want to talk about it although it represents a serious bug for all augmented reality apps. Many developers have reported it and no one has a clue on how to solve it.
The most interesting thread is : forums.developer.apple.com/thread/52145 : CMMotionManager incorrect behavior
However I would like to point out that you can only access this thread using it's url. If you simply go to apple developer forums and do a search using the exact same title, the thread will not appear in the results.
Apparently this is the way apple found to hide it's mistakes. Shame, shame...