The Side Switch can be used for either Lock rotation or Mute. If it is being used for Lock Rotation this can cause Mute to be enabled when the app is launched. Avoid having screen lock on when launching the App.
- Launch the Control Center by swiping up from the bottom of your screen. Look for a bell with a line through it. If the bell is white, tap on it to turn it black (the off position).
- To prevent this happening, go to Settings and change the use of the Side Switch. Tap 'Mute' to make the row show a blue check mark.
- Uninstall and reinstall the app. You will not be charged again.
- If none of the above methods work, try initiating a hard reset. You will not lose any data, apps or anything else, but you will clear any bugs or apps that may be affecting your iPad’s performance. To perform a hard reset, press and hold the power button and the home button simultaneously. Keep them held down for about 20 seconds, or until you see the Apple logo appear on your device, then release the buttons. When the iPad restarts, test your sound.
If this does not fix the issue, can you please let us know which iPad version and iOS you are using (under Settings > General > About > Version).