Auto Updating App with Push Alerts

I want the functionality of https://myproduct.co.il/child-car-check/index.php wrapped into a mobile app that never needs to be rebuilt just because I changed something on the server. All texts, images, logic triggers and any new sections must be pulled dynamically (REST API, GraphQL, or another proven approach you may propose) so a server-side update is instantly reflected in the live iOS and Android builds.

Real-time push notifications are essential. Whenever the server flags an event, users should receive a platform-native alert immediately, even if the app is in the background or closed. No email or in-app only banners—full push is required.

Preferred flow
• You expose a clean, versioned API layer (or connect to the one I already run) that the app consumes at launch and on interval refresh.
• Dynamic configuration (menu items, texts, colors, assets) sits server-side, allowing me to edit a single file or database table and watch the change appear on every device without resubmitting to the stores.
• Firebase Cloud Messaging (or a comparable service) triggers the push alerts, keeping latency to a minimum.

Deliverables
1. Source code for Android and iOS (cross-platform with Flutter/React Native or two native projects—your call, as long as maintenance stays simple).
2. Admin-side guidance: where and how I edit server data to see it propagate.
3. Documentation for publishing, plus a brief video clip that proves dynamic updates and push notifications working in real time.

Please show past work where you implemented a similar dynamic content approach and push notification flow. A short paragraph and store links or APK/IPA test builds are perfect.