Gmail Email Mobile App

I need a lightweight mobile application whose single, clear purpose is to let users send and receive emails from their Gmail account. OAuth-based sign-in, inbox view, compose/reply/forward, and real-time push notifications for new messages are the core features I’m after.

Right now Gmail is the only provider that has to work flawlessly; support for Outlook or Yahoo could be added later, so please structure the code so additional providers can drop in without a full rewrite.

For the push system, use the native notification services on each platform, tied to Gmail’s push endpoints so messages appear instantly even if the app is in the background. Offline reading and queued sending when the device reconnects would be a plus but are not mandatory.

Deliverables:
• Production-ready iOS and Android builds (React Native, Flutter or pure native—your choice, as long as performance is smooth).
• Well-commented source code and a brief setup guide to let me compile and ship future updates myself.
• A short test plan or video walkthrough proving sign-in, email send/receive, and notification flow all work on at least one real device per platform.