As a part of my robot project, i've developed ArduinoCommander application (https://market.android.com/details?id=name.antonsmirnov.android.arduinocommander) to control Arduino board from Android device via bluetooth. You can set pin modes and get/set pin values. All you need is to upload modified StandardFirmata sketch (set baud rate = 9600 instead of 57600 by default) and plug in Bluetooth shield in your Arduino board. It's free.
What do you think about it?