For the electronics I used some simple push button tactile switches. These are momentary so they only hit once. The brain of this was Adafruit's Bluefruit EZ-Key. I wired up 2 switches for the foot pedals and 2 more. One for the Home button in iOS and one for Keyboard Toggle. Everything is concealed with small wooden pushers and a wooden lid. The wooden pushers are glued to insulating foam which acts as a spring surface. The wooden lid attaches using two rare earth magnets. I wired up a JST connector in the final version and attached everything using Adafruit's PermaProto Board. I love these permanent breadboard-esque prototyping boards!
I currently use the app "Setlist" with the pedal. It does a great job at turning the lyrics so we can have a ton of songs in our back pocket with out having to memorize the lyric. As a Bluegrass band, a lot of songs are easily remembered but the lyrics are the hard part!