Give yourself an android friendly manicure with this Adafruit Wearable NFC tutorial
Unlock your phone by just picking it up! No more pesky password or gesture PIN, just scan an NFC tag! This guide covers creating an NFC ring, putting an NFC tag in your nail polish, modding your Android installation to read tags from the lockscreen, and creating an automation toolchain to unlock the phone when the desired tag is scanned.
The software side of this project can be pretty tricky, and even scary if you’ve never jailbroken a phone before, which is required to get the phone to read NFC from the lockscreen.
However, you can still do a lot of fun projects without modding your Android install, just skip that step and head straight to the page about NFC+ Tasker Automation. You won’t be able to log into your phone with your nail polish, but you could do all kinds of other things like start playing Barry White when you place your phone on the nightstand (just sayin’).
The following pages were very helpful while making this guide:
Jon’s guide to bootloader unlocking
chgamauf’s NfcNci.apk mod to poll NFC on lock screen
Eric’s NFC unlock automation toolchain post