You can download the DJay Pro Demo 1.3.1 and unzip the downloaded file. Then find the Pioneer DDJ-SB2.djayMidiMapping file. Copy that file via iTunes onto the iPads documents lib for DJay Pro. Then Djay Pro for iPad recocnizes the controller and voilá 
Works for me Have to use a Powered USB hub though to power the controller, and the camera adapter to connect the hub to the iPad, but it works flawlessly Remember to rename the “Pioneer DDJ-SB2.djayMidiMapping” file to “DDJ-SB2.djayMidiMapping” (just remove the “Pioneer” word) before you put it onto the iPad’s document lib for Djay Pro
