I need a full-featured, small-scale multi-vendor marketplace built natively for both Android and iOS. The app has to let any store—regardless of product type—open a shop front, list items, and receive orders, so the catalog structure must be flexible enough to cover clothing, electronics, home goods, or anything else vendors decide to sell. User roles the system must recognise: - Buyers - Sellers/Vendors - Admin Core flows include simple account creation, product upload with images and variants, cart and checkout, order tracking, and in-app messaging between buyer and vendor. I will also need an admin console (web or app-based) where I can approve vendors, moderate listings, manage commissions, and view analytics. Payment methods to integrate: - Credit/Debit Cards - Bank Transfer - UPI Whichever gateway you suggest just needs to support those three options out of the box. Please ensure secure tokenisation, PCI-compliant handling, and a clean refund flow. The layout should follow modern mobile UI standards—lightweight, fast, and intuitive. React Native or Flutter is fine as long as you can ship to both stores, but if you prefer Kotlin/Swift and can stay within the same timeline, I’m open. Provide source code, API documentation, and a brief hand-over session once the build is stable and passes basic smoke tests on both platforms.