I’m ready to launch a new e-commerce experience and need a developer who can design, build, and customise a mobile application that runs smoothly on both iOS and Android. The overall goal is a polished, production-ready app that lets shoppers browse my catalogue, sign in securely, and checkout without friction. Core functionality I need implemented right away: • User Authentication – email, social, or phone-based sign-up/login with solid security best practices • Payment Gateway Integration – Stripe, PayPal, or a comparable SDK fully wired for real-world transactions Beyond those essentials, I’ll rely on your guidance for a clean shopping-flow foundation (catalogue, product details, basic cart) so the app is immediately usable while leaving room for future feature expansion. Please build with a modern cross-platform stack (React Native, Flutter, or similar), follow platform guidelines for UI/UX, and keep the codebase tidy and well-documented. All source code, assets, and build instructions should be handed over at project completion, along with a brief walkthrough so I can continue evolving the app. If you have a track record of launching secure, high-conversion mobile storefronts, let’s talk about timelines and how you would approach this from first commit to App Store and Google Play submission.