I need a complete mobile car-trading marketplace that mirrors the look, feel, and user flow of olx.ba, but branded for my own venture. The app must launch on both iOS and Android from day one and provide a seamless, consistent experience across the two platforms. Core experience Buyers and sellers will create personal profiles, post vehicles with photos and specs, and interact through an in-app chat. A robust search with granular filters—make, model, year, mileage, price range, location, and more—should let users narrow results instantly. Transactions will be supported by an integrated payment gateway so deposits or full payments can be handled inside the app. I also want friction-free onboarding via social media login. Essential deliverables • Universal codebase that publishes to iOS and Android • Clean, OLX-inspired UI/UX (dark and light modes) • User registration & profile management (email + social media options) • Advanced vehicle search & filtering that feels instant • Secure in-app messaging between buyers and sellers • Payment gateway integration (credit/debit and popular local options) • Admin-friendly listing moderation and user management panel • Thorough QA plus submission to App Store & Google Play Acceptance criteria 1. Both apps pass App Store and Google Play review. 2. Search returns correct results in <1 s for 10 k+ listings. 3. Payments process end-to-end in sandbox and live modes. 4. Every screen adapts flawlessly to phone and tablet breakpoints. Feel free to propose the stack—native Swift/Kotlin, Flutter, or React Native—as long as performance remains on par with modern marketplace apps. Provide an estimated timeline, key milestones, and any past marketplace work when you respond so we can get started right away.