iPhone/iPad//iPod Touch Radio Focus Remote
This is ETC's app for iPhone, iPad, and iPod Touch that allows the handheld to act as an RFU. Cost of the app is $50 and proceeds from the app will be donated to Behind the Scenes (US) or Light Relief (UK). The iRFR app is designed to work with current generation ETC consoles including: Congo/Congo Jr., Eos, Gio, Ion, and Element.
ETC Products - iRFR. See also this thread: http://www.controlbooth.com/forums/lighting/10216-iphone-rfu.html.
For those of the non-Apple persuasion: aRFR.