The HomeKit-friendly version of the August Smart Lock is now available for purchase. Like the original version of the lock, the new model allows you to lock and unlock your home from your iPhone. With HomeKit compatibility, the lock can now connect with your other HomeKit appliances like lights, switches, and more.
In connecting to your other HomeKit appliances, the August Smart Lock can now be controlled with Siri. So you can tell Siri to "lock the front door" and the August Smart Lock will activate. Likewise, you can also place it into scenes, so you can activate, for instance, a "Good night" scene which turns off your downstairs lights and locks your door with one command.
You can pick up the new August Smart Lock from Amazon for $229.99, though stock does seem to be rather limited at the moment.