The guardian project has just released an awesome app for home security. it uses a cheap phone to act as an all in one surveillance device. In a nutshell it uses the phone to record audio, take photos and use the phones gyroscope to detect intrusion data.
The app works via Orbot and Signal to communicate intrusions to either you or a friend. All of the log data is viewable remotely over Tor and you can set a password so only select people can view it.
One of the perks is that its also portable so you can take it with you and use it to keep watch over wherever you are heres the project video below: