Renoise is a keyboard operated thing for sure…It would need a complete redesign to go completely touch…I would certainly welcome such a program, but it would be better to get updates in renoise such as audiotracks and ‘fix the vibrato command’.
For a great portable tracker with multisampled instruments and render to .wav theres milkytracker for PDA (eg. HP-IPAQ enterprise214)
For experimental glitchy textures and wave-scanning style synthesis (but no multisampled instruments) theres LittleGameParkTracker for PSP3000.
For tablets, a more advanced modular synthesis style tracker, sunvox (amazing design and functionality).
There is also a very simple tracker for iphone called ‘sinusoid’.
Nanoloop for iphone and android would have been awesome if it had more patterns per channel (nice one hand usage design).
G-stomper android has had many updates. Its really good…portable sampling electribe with a nice vsti style synth VA-Beast (lots of parameters).
Milkytracker works well for writing a whole tune in a basic chiptune kind of way while travelling or outside.
You can then export to .wav reliably, adding effects in renoise once you are back at your computer.
The control method is stylus + D-pad (two handed wielding is better than cradle+prod / hunt+peck as you find on phones+tablets).
Only problem with LittleGameParkTracker is that its unfortunately not being developed anymore. The windows version no longer works, so no render to .wav. Only headphones out. Also its a homebrew program, no multisampled instruments, no sample editor…But genius design all the same.
Its the best control system out of anything for portability. No need for a table or one tired arm as a result of a phone or tablet held aloft…it is wielded with two hands. Can be quite complex though, a headache when counting ticks, placing HOP commands in tables correctly and such.