MSA Remote is a remote control application for iPhone & iPod Touch that sends OSC messages over the wifi network. This allows you to control any OSC supporting applications such as Max/MSP/Jitter, PureData, Reaktor, VDMX, vvvv, Resolume, Quartz Composer etc.
In this video, OSCulator is routing the OSC (& TUIO) messages coming from MSA Remote to midi and forwarding to Ableton Live and VDMX simultaneously. Nothing is done in post, the same signal is controlling both audio and video.
At the beginning of the video you can see the polyphonic velocity sensitive keys in action (yes, the harder you hit the keys, the louder the sound - works equally well when the iphone is laid on a table), and later on the faders, triggers and multitouch tuio-pad.