Tuckbox

Tuckbox is an MIT-licensed Expo starter using Firebase Auth, Firestore with offline persistence, Cloud Functions and Firebase Cloud Messaging. It ships email, Google and Apple sign-in, a profile screen, light and dark themes, deep links, a settings screen with account deletion as the stores require, and Jest tests with Firebase emulators.

It is opinionated about offline-first behavior, so screens read from the local cache and sync in the background. That makes it a good fit for apps used on the move. The limitation: monetization is not included. There is no paywall or in-app purchase setup, and the README points to RevenueCat without an example.