The Typewriter Dock holds an iPad in its carriage while simultaneously inputting typed letters. You will need a Bluetooth component to replace the cable, and a writing app that can use the accelerometer to detect a carriage return and move you to a new line.
Inside there is a sensor strip under the keyboard which detects the key-presses that hit it, and this pulse of electricity is then passed on to an Arduino circuit-board, whereupon it is translated into a standard USB key-down event. All you need to do is plug it in and type.
Doesn’t the iPad have a keyboard on it already?
what’s the point?