We just couldn’t help ourselves. MIDI Designer is such an amazing program that we couldn’t resist making layouts which control the PX-5S. We’ve done layouts for both the iPhone (iPod touch) and the iPad. These can be download from the downloads section at Casio Music Forums. These layouts gives you control over Zone volume, filters, effects mix, and even some Hex Layer control allowing you to use the physical knobs and sliders on the PX-5S for other things.
These layouts do work on the FREE Lite version of MIDI Designer. You do however get a panel which you have to slide out of the way to access some controls. The full version is well worth its price.
The iPhone version was created using an iPhone 5. We will check it soon on the smaller screen of an iPhone 4 and make some adjustments. While the iPad version is all laid out on one screen, the iPhone version is split between 3 banks and several pages but all of the same control is available.