A simple Android project to control an equipment by arduino and motor control. This is a client server application. You can connect by ip socket if you have router, or wifi direct if you haven't. It's contain a web sever, sou you can remote control by a web browser.
https://www.youtube.com/watch?v=B3gfTJt3DlE
https://www.youtube.com/watch?v=YKyTgjbA5Wc
http://www.instructables.com/id/Android-Arduino-Motor-Control/