6 Oct 2021
All users who have installed that same app (apk file) will get the same stored value.
Note: When we say “the same app” we mean an app with the same name, created by the same developer. For example, if you build an app with FirebaseDB and later modify that app and rebuild it, the new app will still share values with the old app. On the other hand, if you change the name of your project, the old values will become inaccessible. Also, if another developer uses your app source code (AIA file), the resulting app will not share variables with your app, even if the two apps have the same name.
http://ai2.appinventor.mit.edu/reference/other/firebaseIntro.html