Use A Secret Knock To Open Your Door
If you're looking to upgrade your home from smart to Mensa status, Sesame will open that door. Literally. This smart lock system aims to replace your keys forever, with a whole mess of features including remote access and secret entry knocks.
It absolutely destroyed its Kickstarter goal ($392,219 pledged of the $100,000 they asked for) and will be hitting the shelves late spring.
Sesame fits over any existing single cylinder deadbolt lock and pairs with your phone. From there, you can get records of any entry into your home, grant certain people permission without leaving them a key, and even program a knock (to be entered on your phone or on the door itself) that'll open the lock.
Just don't lose your phone.