In the never-ending quest to find a soundboard app without inappropriate sounds for elementary students, I gave up and decided to create my own with my rudimentary knowledge of programming. Look at the various screenshots of the app. There are 48 different sound effects included in the app. If you are interested in the app, please contact me at firstname.lastname@example.org.
Unfortunately I do not know how to program iOS, but my brother does! If there is enough interest, I might be able to convince him to create one for iOS!