Using a free VST app you can use the mic in to control MIDI events. It can be used to control drum machines or simply trigger samples.
Step 1: Equipment and Tools
set of old headphones (only one side needs to work)
empty soda can
cassette tape case (or whatever case you like)
Step 2: Cut a Hole in the Cassette Case
I also cut a notch on the side of the case for the cord to fit out of.
Step 3: Cut the Pads
I cut a second section of mouse pad slightly smaller than the lid of the cassette case.
Step 4: Prep Ear-bud
You can use a pair of broken headphones as you only need one speaker. Cut away the broken one.
Step 5: Glue the Assembly Together
Glue the section of pop can to the under-side of the "trigger pad."
Fit the exposed ear-bud into the hole, and glue the "trigger pad" in place.
Make sure the metal of the pop can that is glued to the "trigger pad" is touching the metal of the ear-bud.
After this was all dry I used black tape to finish off the look and disguise the cassette case.
UNOPAD (get it?)