The MonoBrick remote for android uses a Bluetooth connection and let’s you control the direction and speed of a vehicle by placing your finger on a circle. While driving you can make the phone “read” sensor values aloud. Furthermore the remote let’s you can play sound files, start “on brick” programs and delete files, and last but not least the remote allows you to send raw user input to a mailbox of your choice. This allows you to have a program running on the brick that can react to where the finger is placed on the circle as well as the position of the slider. Read more here. I hope that you enjoy!