I recently purchased an Arduino Due from an $18USD credit from ITEAD. I immediately went searching for something unique to use it for, that's when I found the ElectroSmash pedalSHEILD and thought that's the perfect thing.
Above is a picture off Electrosmash's website showing how it all fits together, below is my finished product.
It took me about two hours to complete the kit. The instructions were clear and precise and plenty of pictures if you needed to double check something.
Below is the ITEAD Arduino Due clone that was purchased separately. This is the only board that can be used with the pedalSHIELD Due, however there's the option for the Arduino Uno called the pedalSHIELD Uno. (not pictured)
At this stage I've tried all the example sketches but haven't had time yet to try my hand at making something uniquely my own sound.