I have an existing app built on Android Native that loads cricket scores and analysis using RestAPI & Firebase Firestore data. We're converting from RestAPI to firebase firestore (realtime data) and app is required to be converted in both Android & iOS.
It uses multiple other json response for app's usability like we do manage ad platform via json (fb/google) and where to load which ads (ad unit id, size, screen/place and if list, after howmany items), to let user know about update app, to get matches which are important & load some match related information (not RestAPI but manual json update)
You can test current version of App here: [login to view URL]
Documentation available for APIs, Adobe XD UI files for both Android/iOS.