Here is the current look of SrutiBox. I've added more "reeds", allow two tonal structures and fixed some rendering bugs.
The intervals it uses for its scales right now are:

1/1 , 9/8 , 5/4 , 4/3 , 3/2 , 5/3 , 15/8 , 2/1 , 9/8' , 5/4' , 3/2' , 2/1'
and
4/4 , 5/4 , 6/4 , 7/4 , 8/4 , 9/4 , 10/4 , 11/4 , 12/4 , 13/4 , 14/4 , 15/4

I don't like the way the UISegmentedControl works, so I'll probably replace it with two (or more) buttons.

I also need a credits page.

Ideally, I should also be able to save the volume set ups under names ... eventually to morph between them would be intense!