There are plenty of smart padlocks available on the market. The 360LOCK is the first one we have seen that comes with Blockchain integration. It is a smart lock you can open or close from your smartphone or using NFC/RFID tag/wristband.
The 360LOCK is compatible with iOS and Android devices. You can manage your locks and share access with others conveniently. The lock is water and dust proof. Its battery lasts for over 1000 openings and closings.