It did cross my mind, but wasn't sure how it handled analog input so thought I'd role my own. Could also of bought a Parrot controller for £40 but there's no fun in that :-)
Espruino is a JavaScript interpreter for low-power Microcontrollers. This site is both a support community for Espruino and a place to share what you are working on.
Nice - thanks for posting up!
Did you consider using the Bluetooth HID option? I think it works with iOS and you might be able to do something that doesn't require an app.
Although having said that it's pretty useful to know how to do everything - doing an app and getting the Puck.js working.