Cool idea, terrible implementation! You have to register every lock you have access to which is a pain when your moving in. Standing in the cold or have your hands full, get out your phone, unlock it, open the app, WAIT, failed, WAIT... oh now the elevator is moving... Guests have to use a complex code, which you have to explain what to do AND there's a different code for EVERY lock. It only works by texting to them or email if they have app access. You can't "buzz" anyone into the building.