For RaspberryPI DIYs
App requires switch-server installed on your RaspberryPi device: https://github.com/sshlyk/switch-server
'Switch' client allows you to control pins on your RaspberryPi device remotely using your phone so you can build all kinds of home automation projects. You can easily hook up your RaspberryPi to a garage door or furnace blower and control it remotely with your phone.
App discovers all Raspberry-Pi devices that run switch-server on your local network so you can control them with a finger tip.
For simplicity and security reasons, app only works when both Raspberry Pi and Android device are connected to the same local network.
Source Code: https://github.com/sshlyk/switch-android