Cross Platform Push Notification App

I’m building a straightforward mobile app that must run smoothly on both iOS and Android. The single, non-negotiable requirement is a rock-solid push-notification feature that works every time, whether the app is in the foreground, background, or closed.

You are free to choose the stack—Swift + Kotlin, Flutter, or React Native—so long as the final binaries pass App Store and Google Play review and the notification flow is fully documented. I will provide the certificates, keys, and any server-side endpoints you need; I just need you to wire everything up, test it end-to-end, and hand back a maintainable codebase.

Deliverables
• Complete source code for both platforms
• Configuration for APNs and FCM (or a unified service such as Firebase Cloud Messaging)
• Step-by-step build & release instructions
• A brief test report proving that notifications arrive reliably under different app states

If you have shipped cross-platform apps with flawless push support before, I’d love to see your work and get started right away.