A few notes.
- You can't re-write this tag using the Moto X. The NFC service intercepts these tags and won't deliver them to another app to write (even with foregroundDispatch set up as far as I can tell). You can freely overwrite it with any other device though and it will work with any app again on the Moto X
- This should allow you to use a tag as a Skip tag as well as expose the NFC Lock Screen option and Manage NFC Unlock options under security settings (see screenshot) if you don't have an official skip tag. Using this you can create new skip tags using any writable tag and add them to your supported tag list.
Grab it here: http://goo.gl/5bUqPW
NFC Lock settings