this method is called in case the current device is capable of delivering device motion data This method is called in case the device returns YES for the CMMotionManager property deviceMotionAvailable and the CMMotionManager property availableAttitudeReferenceFrames contains the reference frame that was returned from the WTExternalCMMotionManagerDataAccessMode class method +requiredAttitudeReferenceFrameForFeatures:

A typical implementation looks like this:

• (CMDeviceMotion *)currentDeviceMotion { return self.externalMotionManager.deviceMotion; }

this method is called in case the current device is not capable of delivering device motion data

A typical implementation looks like this:

• (CMAccelerometerData *)currentAccelerometerData { return self.externalMotionManager.accelerometerData; }

this method is called in case the current device is not capable of delivering device motion data or is running iOS 10.0.x until iOS 10.1.0

It’s implementation is supposed to return the heading that is available from the CLLocationManager class.