OTP-Based Android Shopping App

I’m building a native Android application that lets shoppers register quickly with nothing more than their phone number and a one-time password. Once inside, users should be able to browse all items through a clean category filter, view product details, add items to a cart, and place orders in just a few taps.

Core flow
• On first launch, the app asks for a phone number, sends an OTP, and authenticates the user.
• The home screen loads product categories pulled from a backend (REST or GraphQL—whichever you prefer). Inside each category, items appear with thumbnail, price, and short description.
• Tapping an item opens a detail page with images, variants, and an “Add to Cart” button.
• Checkout accepts mobile wallet payments (Google Pay, Samsung Pay, etc.) and returns a success or failure status that we log server-side.
• After purchase, the user can review past orders in a simple “My Orders” screen.

I’ll supply product data endpoints and basic UI wireframes; you handle Android Studio setup, phone-number/OTP authentication (Firebase Auth is fine), wallet integration, and final APK/AAB delivery. Source code should be clean, well-commented, and Git-ready so my team can maintain it later.

Acceptance criteria
1. Phone-number sign-up/sign-in with OTP, no email or social login.
2. Category filter browses products pulled live from the API.
3. Fully working cart and order placement.
4. Mobile wallet checkout returns verified transaction IDs.
5. Code compiles without errors in Android Studio Flamingo or newer.

Let me know your lead time and any SDKs you plan to use so we can lock this in and start testing.