We've seen a lot of smartphone-controlled devices taking on home security lately--from the Scout full home security system to DoorBot, a camera-digital locking system combo that shows who's at the door and allows homeowners to converse with and choose whether or not to let them in. The August Smart Lock, a digital door lock, seems to be a more streamlined version of the latter. It retrofits to existing single-cylinder deadbolts and communicates with a companion smartphone app to grant owners, and others in owners' good graces, keyless, automatic door access, but loses DoorBot's camera/streaming video properties for a more compact and low-profile look.
August Smart Lock eliminates the need for entry keys or codes (though if your phone dies or you don't have it for some reason, the lock can still function with a standard key.) Those in control of its app also have full control of August's encrypted locking technology, which can be programmed to unlock at the press of a fake touchscreen button, unlock automatically as you near the door, or to provide access to someone else. Someone else access can take on many forms--a single entry you approve in real time for a delivery person, a pre-approved single entry for party guests, a few hours of in-and-out use for the babysitter, once-a-week use for housekeeping, or 24/7 use for your...well I'm not going to say booty call because that would be impolite, but you can think it if you want.
August keeps logs of who has entered and exited its door and when, and its distributed digital keys can be enabled or disabled at any time. If cable (you can also access August from a computer) or WiFi go down, August's standard backup batteries will keep it running. Physical installation takes about 10 minutes, and does not require changing out door hardware. The system is compatible with iPhone and Android as of now; BlackBerry and Windows Phone 8 are to follow.
For more information and rebuttals to your, "Yeah buts," check out August's FAQ page.