Darryl is at it again, with a new Android app called PIC32USB, providing OTG-supported phones/tablets with a hardwired communication to a PIC32 microcontroller. Use any of the 24 buttons to send messages to the PIC32 device, customize any button to change the string sent to the device, and send/recieve data to/from the device using a chat-like interface. Check out his sample code to test it out on your OTG-supported mobile device and your supported PIC32-based board. Darryl has successfully tested this app with the chipKIT Fubarino SD, chipKIT Fubarino Mini, and his very own MAKEmicro32 board.
Good luck, and have fun out there!