The app is called "Prank Record" and the idea is fairly simple. Record a message, and then set a time for it to be played back. There is an option to setup the play back on repeat (which repeats at the same interval that you set the play back delay for) if you would like. The play back works as a service so you can close the app and the play back will still occur at the time interval. If you want to stop the play back/timer just go back into the app and click the "Stop" button.
Here are some examples of uses:
Record a whisper of someones name. Set the timer for a couple of minutes then hide your phone somewhere in a room near the person and laugh hysterically as they try to figure out who is calling them.
Record a loud shriek, set the timer for 15 minutes and place your phone by your spouses/roommates/parents night stand as they are going to sleep. Right as they doze off the sound plays scaring them out of their sleep.
If this app gets a decent amount of downloads I will update with some other features shortly. Thank you and I appreciate any feedback!