I don't know how this one skipped under the radar, I believe this is the only "true" multichannel sound card for IOS, theres the behringer UFO which will do stereo ok.
But in theory given that this is a 4channel recording interface theres a possibility to use an iPad as a DVS solution (if someone will get off their backside and do it)....
Mixxx for iPad perhaps - ohhh wouldn't it be nice :D