Cross-Platform E-Commerce Mobile App

I need a polished e-commerce mobile application that launches on both iOS and Android from a single codebase. The app should let shoppers smoothly browse a catalogue, add items to a cart, complete checkout with secure payments, and follow their orders in real time... (Budget: $30 - $250 USD, Jobs: Android, Flutter, iOS Development, iPhone, Mobile App Development, PHP, React Native, REST API)