I am close to putting an app on beta and I need some beta testers, I have about 60 people from my team already,
What you have to do is:
1. Use the app to call, and free to test it out.
2. take photos, do video chatting with your friends to make sure the app is not lagging or to test and make sure it is flowing properly.
3. Do some live streaming and create a channel where you can broadcast yourself.
4. make voice calls to make sure all is working properly.
5. create your profile and add photos do group chats, etc....
and a few other things app related that might come up.