With August Smart Lock, your smartphone is the key

Smartphone users, kiss that bulky key ring goodbye. The August Smart Lock, from entrepreneur Jason Johnson and designer Yves Béhar, leads a wave of new devices that automatically unlock the front door. Questions abound: What if you lose your phone? Can someone else use your phone to break into your house? There are security features that address these concerns and more, and at least 30,000 people have reserved the device, available later this year. Here's an inside look at, well, how it gets you inside.

A quick install

Unlike some of its competitors, August takes up just one side of the door. It replaces the thumb latch on the interior side of the existing deadbolt. That makes installing the lock a process that takes 10 minutes or less.

Energy-saving connectivity

Instead of a physical key, users download a smartphone app that securely communicates with the lock over a low-energy kind of Bluetooth. Options include having August autolock and unlock when users are feet away or tapping a virtual button to do the job.

Virtual keys, as you please

The best part? Users can easily grant access to friends and family with in-app invitations. The virtual keys can be customized to work during set hours or to expire after a specific date -- in case, say, the babysitter needs to get in.