I think I found the "Untrusted Developer" root cause!

Within a narrow window, I replaced the phone and upgraded to Xcode beta3.  This wound up having quite a few provisioning profiles associated with the phone known as "Greg's iPhone".  To fix:

• Xcode
• Devices menu
• Select offending device
• Right click Profiles
• Delete all of the provisioning profiles
• Then re-launch, re-install the applications

All the other attempts, like re-pairing phone, full restores, and so on masked the root cause, and worked typically one time.

Now back to CoreMotion library.  I've got accelerometer output working -- too bad it isn't supported on simulator.  Next up will be the CMDeviceMotion higher level data.