You can now lock your door from anywhere in the world. Lockitron is an awesome new piece of technology designed to let you unlock your house using your smartphone. Lockitron installs over almost any deadbolt, so users do not need to add anything special in their door.

Lockitron can be used differently depending on what device the user is using. Assuming that the user has an iPhone, the Lockitron utilizes Bluetooth 4.0 to sense when the apartment resident or homeowner is approaching and will automatically unlock the front door without any interaction from the user. Android users will be able to wave their NFC-enabled device in front of the door in order to gain entrance. After the user has entered the building and closed the door, the Lockitron automatically engages the lock again. Even users without smartphones can send a text message to Lockitron to unlock their door.

The device also has a knock sensor. If someone knocks on the door, the homeowner will receive a notification informing them of an arriving guest. It also has an unlock sensor, so if someone uses a traditional key to gain access to the house, the main user will be notified.

Source: https://lockitron.com