My daughter and I have had fun creating four layered beats with BeatWave. I free iPad app that allows you to select a series or patterns of tones to make a cool collection beats. The really cool part was when we started experiment with the patterns that make the visual representation of the beat. It did have a feature to email the beat, but I am not sure how it worked once you received the email.
If you want to have some fun find a friend when you might check it out!