Tech enthusiasts will recognize August Smart Lock as the DIY security device that allows homeowners to create virtual keys for guests to come and go. Design seekers will notice the second-generation lock, soon to ship, has a more tactile, intuitive form profile that resembles a traditional knob. The latest model is also Apple Homekit enabled.  Photo 1 of 6 in 5 Key Elements of Smart Home Functionality from Buzz-Worthy Smart Home Innovations Coming Out of CES 2016