Smart locks make it possible for you to double check and make sure that your door is locked no matter where you are. Smart locks can replace current deadbolt locks and sync up to your phone so that you can unlock your door just by walking up to it. The technology knows not to unlock it when you are just passing by inside of the home, however. You can also unlock the door for guests. You will be alerted if someone has tried to unlock your door, and you can even see and talk to your guests using some smart locks.