Mouse On Mars WretchUp iPhone App November 12, 2014 by iPad Loops, Music Production Apps, And Hardware 0 An effect instrument anyone can play, from Mouse on Mars. It’s sonic anarchy in the palm of your hand. WretchUp is the sonic instrument from the imagination of Mouse on Mars Instruments. Used by... Effects, Looping Apps iphone app, iphone sound effects, mouse on mars, Mouse On Mars WretchUp iPhone App, wretchup.