I want to launch a mobile marketplace dedicated entirely to bikes—something that feels as smooth as OLX but is streamlined for one product category. I already decided on Firebase and React native for every layer of the stack, so the job covers both the real-time back-end and the complete app interface. Core scope • Listings: users must be able to post, edit, browse and search bike ads in real time. • Transactions: the primary flow is buying / selling bikes; no bidding or payment gateway for now. • Chat: real-time, one-to-one messaging between buyer and seller inside the app. • Authentication: phone-number login via Firebase Authentication only (no email or social options). Tech baseline Firestore (or Realtime Database if you prefer and can justify), Firebase Auth with SMS verification, Cloud Storage for images, and Cloud Functions where server logic is unavoidable. The interface shoild be in React Native while still keeping the codebase clean and maintainable. Deliverables 1. Firestore data model, security rules and any Cloud Functions scripts. 2. Fully functional mobile app (source code + build instructions) implementing the flows above. 3. Simple, modern UI/UX: splash, onboarding, listing feed, detail page, chat screen, profile & post-ad screens. 4. Basic admin access (even a simple Firebase console setup is fine) so I can review or remove listings. 5. A short hand-off document and walkthrough video. I appreciate clean, well-commented code and incremental builds I can test on device. Let me know the framework you recommend, a ballpark timeline, and any similar Firebase projects you have shipped.