Android POS App + Source

I need a production-ready Android POS application delivered with complete, unrestricted ownership of the full source code.

Core scope
• Sales reporting dashboards and printable summaries are the priority.
• The app must process payments through popular mobile wallets (for example, Google Pay or any SDK you recommend).
• Full offline functionality is essential so the cashier can keep working without internet and sync automatically once a connection is restored.

Tech expectations
You may code in Kotlin or Java and are free to use Android Jetpack, Room, or other standard libraries as long as the final build installs cleanly from Android 10 upward. Clean architecture, clear code comments, and a brief setup guide are mandatory so I can compile and sign the APK myself.

Deliverables
1. Compilable Android Studio project with all source files.
2. Signed APK for quick testing.
3. README documenting build steps, libraries, and how offline sync works.
4. Short video or screenshots that prove the sales report flow, mobile wallet checkout, and offline mode.

Future extensions such as inventory or employee management could follow, so design with modularity in mind. Let me know your estimated timeline and any third-party costs up front.