My production Flutter app is live on Android and iOS phones right now, but I need to push it much further so it also shines on tablets and a Windows desktop build. The next release must feel polished, run offline without hiccups, and bring serious value-add features that keep merchants and their customers engaged. Core scope • Offline-first architecture with local persistence and an auto-sync routine that silently pushes queued actions once connectivity returns. • A chat-style, rule-based onboarding that walks new merchants through business registration step by step, validating inputs on the fly. • Referral and rewards module focused on a wallet / credit balance. Every reward earned, spent, or expired must update instantly in the user’s local ledger and sync to the server when online. • Digital warranties generated at checkout and shared via email or WhatsApp in a tap. • Receipt generation after each transaction, likewise shareable. • Bulk SMS and email broadcast tools so merchants can run promotions or send updates. • Analytics dashboards with daily, weekly, monthly, quarterly, and annual views. • End-of-day close that rolls up sales, rewards activity, and inventory movements, then pushes a summary notification to the business owner. • Responsive, adaptive layouts so the UI stretches naturally across 7-inch up to 12-inch tablets and the Windows desktop window. Tech stack expectations Flutter (current stable channel), Hive or Drift for local storage, REST or GraphQL to my existing backend, Firebase Messaging for notifications, and any credible analytics package you prefer. Clean architecture, null-safe Dart, and provider or bloc for state management are required so the codebase stays maintainable. Acceptance criteria 1. Switch device to airplane mode, complete key workflows, restore connection, and see data fully synced with zero duplicates. 2. Onboarding flow must be completable in under 3 minutes using only the on-screen chat prompts. 3. Wallet balance always reconciles with server values after sync. 4. All shared receipts and warranties open correctly on Gmail, Outlook, and WhatsApp Web. 5. Tablet UI scores 90+ on Flutter DevTools’ layout guidelines. I will supply the existing repo, API docs, and Figma screens for the new modules. Let me know which part of this roadmap you would tackle first and an outline of your approach.