What does the mute switch on the iPad do?
The iPad mute switch is identical to the iPhone's mute switch except it can't control a ringer/vibration choice. Other than that, it's effect in-app will be identical.


Not all apps respect the 'mute' switch. Apps that have no purpose EXCEPT to be listened to (music apps, youtube, etc.) will not be any different in either switched mode.
Frequently, games or other apps with "ambient music" will silence the music and often the sound effects as well when the switch is set to mute.


It is due to this inconsistency that I choose to set the switch to control orientation lock, and just use the volume controls as needed.