Hey there,
First off I want to let you know that I absolutely love your product. I've been using it in my rock band during live performances creating loops live running through my Digitech Jamman looper pedal in which a record a loop and pop it on during a chorus or something of that nature.
The feature I would really love to see would be a key or scale lock so that when I'm switching from instrument instrument I don't have to keep changing the last setting in which the instrument was left.
Thanks so much for bringing ThumbJam to the world.
Key/Scale Lock
In the instrument chooser,
In the instrument chooser, look at the bottom for a switch called "Keep Current Scale/Key", when that is switched on it will maintain whatever key/scale is currently active.