The latest smart locks offer things like voice activation, geofencing, and auto-locking features. With voice activation, locking and unlocking doors is as easy as it gets; simply tell your phone to "unlock the front door," and the lock will disengage. With geofencing, you'll never have to worry if you locked up before you left the house; just use the mobile app to set up a perimeter around your house, and use your phone's location services to pinpoint your exact location. When you leave the perimeter, you can have the lock automatically engage behind you. Similarly, an auto-lock feature will have the lock automatically engage after it has been unlocked for a specific period of time.