A new smart lock is on the market from Netatmo called the Netatmo Smart Door Lock, and it can be installed as a replacement for any cylinder lock of the sort common in Europe. The device is interesting in that you can use a smartphone or a physical key to open the door.
The key itself isn’t a standard key; it’s an NFC badge that is shaped like a key. The lock can be programmed to authorize the key or not. That means if you lose a key, it can be deauthorized.
The system also allows one key to be used for multiple locks around the home or at different locations. The system works with a smartphone, too, and allows you to send someone an invite to get into the home so visitors can gain access reports TechCrunch.
Another important thing about the lock is that it uses Bluetooth, not WiFi, so the lock is never connected to the Internet. An integrated accelerometer helps to detect break-in attempts. There is no subscription fee, and the device works with HomeKit. Pricing and availability are a mystery.