Annoydio jr

Annoydio jr has a grid of pads which you can assign, manipulate, and play sounds. There are built in sounds and one custom sound. With the custom sound you can record anything you want and then play it back on a pad or with full polyphony using a MIDI keyboard or Inter-App Audio host that supports remote instruments.
You can manipulate the sounds by changing the frequency, playing in reverse, looping, adding effects such as distortion and delay. You can also change parameters such as attack, decay, sustain, and release.
If you like Annoydio jr but want more built in sounds, the ability to create unlimited custom sounds, and the ability to bounce sound selections then try Annoydio http://itunes.apple.com/app/id671684127?mt=8.