I need an Android-only e-commerce application whose first release concentrates on a smooth shopping-cart flow and a secure, hassle-free checkout. Think of it as the purchasing core of a larger store: products are already stored in a backend API I provide, so your mission is to turn browsing items into confirmed orders with as few taps as possible. Key requirements • Kotlin (preferred) or Java inside Android Studio • Add-to-cart, quantity edits, promo-code handling, and real-time basket total updates • Multiple payment gateways (Stripe is mandatory; PayPal is a nice-to-have) with tokenised, PCI-compliant processing • Order confirmation screen + push/email receipt trigger • Clean MVVM architecture, Retrofit for API calls, and Firebase Crashlytics for basic analytics Deliverables 1. Signed APK for internal testing and a Play-Store-ready build 2. Full, well-commented source code in Git 3. Short hand-off document describing build steps, dependencies, and how to point the app at staging vs. production endpoints Acceptance will be based on: zero crashes in a 50-item checkout test, payment gateway passing sandbox certification, and Play Console pre-launch report showing no critical issues. The iOS version and extras such as user profiles can follow once this core is solid, so build with scalability in mind. Let’s talk timelines and any library preferences you have.