Cross-Platform E-Commerce App Development

I’m ready to turn a new e-commerce concept into a polished mobile experience that runs smoothly on both iOS and Android. The core build must include:

• Secure user registration and login (email, social, and OTP options)
• Fast product search with category and attribute filters
• Reliable payment-gateway integration that supports cards, wallets, and local methods

Beyond those essentials, I’ll need a clean product catalogue UI, a lightweight cart and checkout flow, and basic order-tracking screens. I’m open to React Native or Flutter if it keeps one codebase, but native Swift/Kotlin proposals are welcome so long as feature parity is guaranteed.

Please outline your preferred tech stack, any relevant live apps, a realistic timeline, and how you’ll handle testing, store deployment, and a brief hand-off session so I can manage routine updates after launch.