Well I was searching the app store for such an app where the alarm or reminder shuts off after it goes off and the app is called ALARMED it has three settings reminder,timer and alarm now if you select reminder and set it for the time you want to wake up and I have tested it out it the sound plays once then stops perfect for an can wild alarm!!!!!!!!!!!!!

HOPE THIS HELPS AND BY THE WAY THE APP IS FREE IT IS CALLED ALARMED