I need a cross-platform mobile application for iOS and Android that lets users buy and sell digital photos and videos. Sellers must be able to upload both photos and videos directly from their phones, set a price, and publish listings; buyers should then browse, preview watermarked media, purchase, and download their files inside the app. Key functionality I’m looking for: • Account creation via email/password with the option of social media login. • Seamless photo and video upload, automatic compression, and watermark overlay. • Marketplace essentials: search, categories, favourites, push-notification updates, in-app chat between buyer and seller, and an order history screen. • Secure checkout using a mainstream gateway such as Stripe, plus a payout flow that lets me keep a commission before sellers receive funds. • Basic web-based admin panel to review uploads, manage users, and export sales reports. • Clean, intuitive UI built in React Native, Flutter, or a comparable cross-platform framework—happy to take your recommendation. Deliverable: a working prototype ready for TestFlight and Google Play Internal Testing, complete with source code, installation notes, and clear comments so I can extend the project later. When you reply, please specify your preferred tech stack, any related apps you’ve delivered, and a realistic timeline to reach this prototype stage.