I need a well-structured Android + ios application that supports the core activities of my app. The build should run smoothly on the latest Android versions, with backward compatibility to at least Android 9 +ios. Main function: will be added later as l find the right Freelancer Core functions I must see working end-to-end: • Secure user authentication (email or social login is fine, but tokens must be safely stored). • Reliable push notifications so I can share updates, offers, or urgent messages in real time. • In-app purchases, fully integrated with Google Play Billing, for selling digital items or upgrades. • A clean communication module—think in-app chat or messaging—to keep users connected with support or with one another. I’m open to Kotlin or modern Java, and Firebase is perfectly acceptable for auth, notifications, and real-time communication if that speeds things up. Clean architecture (MVVM or similar), sensible package structure, and clear documentation are must-haves; I plan to maintain the codebase after launch. Deliverables: 1. Complete, readable source code in a Git repo. 2. Release-ready APK plus a debug build for testing. 3. Setup notes that cover build steps, environment variables, and how to connect any third-party services you choose. 4. A brief test report confirming that login, notifications, purchases, and messaging all function on at least two physical Android devices. Timeline is flexible within reason, but I’d like to see an initial working prototype within a few weeks so we can iterate quickly.