Newcomer August takes on the smartphone-controlled door lock with the August Smart Lock-- a lock module and free online service combination allowing customers to unlock doors via Bluetooth low energy (BLE).
Making the lock module rather interesting is not the striking Yves Behar industrial design (although it does remind us of the Nest thermostat) but its security features. It uses BLE and a paired smartphone or tablet instead of wifi to connect briefly with the August online service. Once the module syncs with the service it assigns an algorithmically generated key to the paired mobile device, thus avoiding the risk of hacking internet connections involve.
Individual "key" management comes through an app (iOS and Android) complete with granular remote access controls, such as allowing access to particular individuals on specific dates/times.