In the past few years, we have covered plenty of smart locks here that can be unlocked and locked from a smartphone. The 360LOCK takes it to the next level. It can be controlled from an iOS and Android device as well as using a NFC/RFID tag or wristband. More importantly, it relies on Blockchain for security.
The 360LOCK can be managed from your smartphone, so you can add keys for more users and track multiple locks. The lock is waterproof and dustproof. Its battery lasts over 1000 openings/closings.[where to find it]