I need a production-ready Flutter application, delivered within the next two months, that matches the look-and-feel and core workflow of the “Hisab – GST Accounting” app I’ve linked above. The build has to run smoothly on both iOS and Android from a single codebase. Core scope • Expense tracking, invoice generation and automated GST calculations must work end-to-end offline and online. • Secure email / password authentication is mandatory; please wire it cleanly into Firebase Auth or another proven solution. • The app will connect to at least one payment gateway and a basic CRM endpoint so transactions are recorded in real time. I’ll supply the API keys and endpoint docs once the project starts. Tech expectations Flutter 3.x with null-safety, state management via Provider or Bloc (open to your preference), and clean architecture so future modules can be slotted in easily. The code has to compile without warnings, be fully commented, and follow Dart’s effective style guide. Deliverables 1. Source code in a private Git repo with clear commit history 2. Two platform builds (TestFlight + Google Play Internal Testing) 3. Setup notes and a concise README so another developer can reproduce the build in one sitting 4. A brief demo video walking through the finished features Acceptance criteria • All three core features work as described, with calculations matching Indian GST slabs. • Authentication flow passes standard security checks (rate limiting, email verification). • Sample payment and CRM calls complete successfully using sandbox credentials. • No critical or high-priority issues in the final QA round. - also upload in play store and apple store If you’ve shipped finance or accounting apps in Flutter before and can hit the two-month window, I’d love to review your approach and timeline.