Use the Simon by clicking or pressing the number keys 1-4. Each beat will be added to the loop. Press Space to replay the loop. Notes played while the loop is looping will not be added to the loop. Press Space again to stop the loop. The rest button (5 key) will add a rest to the loop.
Inspired by... Simon. Credits to... Simon. Yes, these actually are the pitches from the real Simon game, although the colors are in the wrong order.