Apple today released its third beta of iOS 8.3 to registered developers for testing purposes. The beta arrives as build number 12F5047f. For known issues read below:
Notes and Known Issues
The following issues relate to using iOS SDK 8.3 to develop code.
App extensions need an arm64 slice to run on 64-bit devices. If you try to run the armv7 slice on a 64-bit device it won’t work.
Apps need to have an arm64 slice if the bundle contains a framework that both the app and the app extension link against.
Outgoing Call Audio and FaceTime Audio may be choppy.
3rd Party keyboards may not be available for selection in Spotlight Search.
Workaround: Reboot the device.