It strikes me that it would not be that hard to code an app for the iPad (or a Windows tablet, whatever) to add a Chord Sequencer to any arranger out there.
Basically, all it has to do is slave to the arranger's tempo clock (easy), receive the NTA (notes to arranger) channel from the arranger, and loop the MIDI recording and play it back when the Play button is hit. Hardly as complicated as a full sequencer...
I'm pretty sure this would sell very well. Anyone know anyone doing MIDI app development for iPad or other devices?
I have been hunting this for some time Diki, including speaking with developers. Also along the same lines, it is essentially midi data only etc etc etc..
They all have said with the cost of developing apps of this nature being anywhere between $5,000 to 10,000 and the prospect of returns so low for such a "specific" market, that they could not be bothered to do it off their own bat...
However if a "Kickstarter" scheme were suggested, perhaps a developer may have an interest.
None of the current software arranger developers have any time to port versions to iOS.
As Abacus has pointed out, you could always get the developer SDK packages (requires registration and sign-up, but is free) and start writing your own..but fair warning, it is far FAR more difficult than it first looks. Believe me I have already tried...WAY above my level of mathematics and logic
Dennis