Intuitive E-Commerce Shopping App

I run an established e-commerce site and now need a companion mobile app that feels as smooth as the web store while adding the convenience of native shopping. The build has to ship on both iOS and Android from the same codebase (React Native, Flutter, or a comparable cross-platform framework is fine as long as performance remains high).

Core experience
• Shoppers open the app, browse every product already live on the website, add items to cart, and check out without leaving the app.
• The interface must resize gracefully on phones and tablets, portrait or landscape. Swipes, lazy-loaded images, and search/filter functions should feel instant.

Account & security
Sign-up and log-in rely exclusively on phone number verification—no email or social accounts at this stage. Please factor in OTP handling, resend limits, and secure token storage.

Payments
During checkout the app needs to process Credit/Debit cards and PayPal natively. Use a PCI-compliant gateway (Stripe, Braintree, or another you already master) so I remain covered on compliance. Leave hooks for additional digital wallets later, but they are out of scope for this release.

Admin side
Products, pricing, inventory, and order statuses already live in my website’s database. The app should pull and push through the existing REST/GraphQL endpoints; if a connector layer is required, note it in your plan.

Deliverables
• Production-ready iOS & Android apps, approved in both stores
• Source code with clear README for future maintenance
• Brief hand-off session (recorded) walking through build, deployment, and environment variables

Acceptance criteria
1. User can register/login via phone number and purchase an item end-to-end with real payment in sandbox mode.
2. Cart, order history, and push notifications mirror website data.
3. No critical UI/UX issues across latest two major OS versions on common devices.

If you’ve published similar commerce apps before, especially with card + PayPal flows, your insight will be invaluable. Share a concise timeline and the stack you recommend, and we can get started right away.