> If you use GrapheneOS, you can enable or disable internet access for each app.
Not sure what information you're expecting the app in question to surface if you disable internet access for it.
geo-positioning, maps, way-finding, directions, time of day, calendar, lunar cycle, calculator, notes, language translation, calculator, games, contacts, etc.
Locally stored info
An error? It's useful to know if/when an app wants to access the Internet. So if an app says it's local only you can disable network permissions. Trust but verify.