MCH is probably the simplest and most straight forward "rotation" such as it is. If you're just looking for simple, MCH is it.

RDM is also pretty simple and is actually has a very nice rhythm to it, so that might help with the ADD. You are filling up a bar and trying to keep two sides of the bar relatively even, so it does provide some structure, which may help or may not help with the ADD aspect depending on your particulars in that regard.