README
Provides code for FSK communication between the Arduino and iOS/Android devices via the microphone input line on a TRRS jack. More documentaion can be found here: http://www.creativedistraction.com/demos/sensor-data-to-iphone-through-the-headphone-jack-using-arduino/
Source code for iOS can be found here under serial modem: http://labs.perceptdev.com/iphone-hacks-source-code-2/