I've just bought a midi piano accordion, a Roland FR1-x and looking to ease my way into playing it, have stumbled across Piano Booster. One of the problems with the accordion is the left hand .... all those little buttons to press .... and you can't even see them!
Piano Booster helps a great deal, but where it could REALLY help is to have a screen that 'reflects' pictorially a 72 'Stradella' bass layout ... Lighting the named keys as the player plays them. This would be a great help for a learner to 'feel' his way around the bass section of the accordion. Such a diagram is below: