With a rooted Android (still stock ROM) and these two elements it's possible to use the NFC Ring to unlock the native Android lockscreens (pattern, pin, whatever). In fact it works better because it still unlocks even when giving a 'bad read' sound, presumably because it isn't interested in the contents just the UID.
The only thing to watch out for is that you'll get the 'new empty tag' message popup when you unlock, and some have suggested using the Disable NFC Tag Empty Message module, but that only works when lock screen is on ... so if you get two rapid reads the second could happen once lock screen is removed and you'll still see the message.
The best method I found is to just register the ring with the NFC Ring Unlock App, which will write something to it that no other app is interested in! Hey presto, you can unlock the standard lock and not get extra messages pop up.
Good post man.
You're right, it's based off UID only, so if it can read long enough to give the failed read sound then it'll still unlock cos it'll have the UID. I played around with it for ages doing that, making sure that it wasn't just unlocking for any old device.
Something you can do that's interesting and bypasses the empty tag message is to encode an action for the ring, like in my case I read a lot so I have a good selection of ebooks and my reader of choice. Setting up the ring as both unlock-allowed and also to trigger the ebook I'm currently reading lets me unlock the tablet or phone with a quick swipe and the "failed read" sound, and with a longer "successful" read it'll both unlock and launch my book.
It's fiddly for a start but after practice it's second nature.