Mobile devices have been integrated into our daily lives. As a result, home automation and security are becoming increasingly prominent features on mobile devices. In this article, we have developed a security system that interacts with an Android mobile device. The mobile device and the security system communicate via Bluetooth because a short-range communications system is desired. The mobile application can be loaded into any compatible device, and once loaded, interface with the security system. The commands to lock, unlock or check the status of the door to which the security system is installed can be sent quickly from the mobile device through a simple and easy to use GUI. The security system then acts on these commands, taking the appropriate action and sending a confirmation back to the mobile device. The security system can also inform the user if the door is open. The door also incorporates a traditional lock and a key interface in case the user loses the mobile device.