we would love to help as best as we can!
but only with full and specific details, we can provide efficient support to you.
as has been stated here, "my friends has downloaded the app, and the message "your app encountered a fatal error" keeps popping up"
we will need to know the followings:
1. your friend's smartphone model, Android version, OS version, etc.
2. which APP version has been installed?
3. what can you see when the APP is started?
A screen video to show all these details above will help us a lot!
so we can check and confirm all your details and provide a solution or a workaround.
By the way, which smartphones of yours are available for testing now?