Hi!
Is there a particular reason that you’re concerned about end users finding your App ID?
A Realm App ID is a non-sensitive, public ID so there should be no reason to hide it. That is, if someone has your App ID they can’t do anything they couldn’t already do with your app.
The reason this works is because Realm (a) makes you log in with user-specific credentials and (b) enforces rules on the backend - these are your app’s security measures and end users have no way to view or modify your rules.