This American Loopers Aux For Digitech Jamman will allow you to control Reverse, Undo/Redo and Time Stretch.
We also made the center switch a bit higher to avoid hitting the two switches at a time (see pic). It also has the nice Click-Less switches to make it even nicer!
4.39 x 2.34 x 1.06
* You will need a TRS Cable for this pedal to work, you can GET IT HERE