No, they dont. I wrote the app...
I also have a non-MIDI version that has just an accordion sound, but this is the MIDI controller version.
Looking farther on in the video, it looks like hes using a number of other synth apps running in the background on the iPad including the Roland Sound Canvas app.
iOS is amazing that way, you can have multiple synthesizer apps all running in the background on a device listening for MIDI events on different channels being sent by a controller app like mine.
Based on his suggestions, I released an update to the app that will allow you to setup and switch between 4 different MIDI presets of channel, volume, velocity, and transpose as well as add a +/- octave selector to the treble side (also saved with the preset). Now available on the iTunes App Store. Did the same thing with the presets for the Hohner MIDI Piano Accordion controller (need to still add the octave selector in a future update).
More info at:
http://www.tradlessons.com/HohnerMIDIChromaticAccordion.html
New preset control at the top of the play surface, octave control at the bottom:
C-system:
<ATTACHMENT filename=IMG_2677.jpg index=1>
B-system:
<ATTACHMENT filename=IMG_2679.jpg index=0>
New preset selectors on the MIDI controls page:
<ATTACHMENT filename=IMG_2668.jpg index=2>
