Android E-Commerce App Development

I need a polished, production-ready Android application focused entirely on e-commerce. The core requirement is a smooth buying journey—from browsing products, adding items to a cart, and completing a secure checkout, through to receiving order confirmations and basic status updates.

The app must be native for Android (Kotlin or Java are both fine) and follow current Material Design guidelines so it feels at home on modern phones and tablets. I already have product data and imagery prepared; what I need is the technical build, an intuitive UI/UX, and connection to a payment gateway such as Stripe or Razorpay.

Please include:
• Clean, well-commented source code hosted in a private Git repository
• A fully signed, Play-Store-ready APK or AAB
• Simple admin or API hooks so I can add, edit, or remove products without touching the code

Deliver the project in logical milestones—prototype, beta, and final release—so we can test on real devices throughout. If you have previous Android e-commerce examples, share a link or APK; seeing your work will speed up selection.