I’ve just submitted updates to Apple for both the Hohner Piano and Chromatic SqueezeBox apps adding a new option to select between Bass/Major/Minor/7 or Counter-Bass/Bass/Major/Minor configurations on the bass side.
Here’s a couple of screenshots:
Piano version with the counter basses enabled
Chromatic in C-system and the counter basses enabled
Look for both as free updates on iTunes around September 9th.
Cheers and thanks!