Project Overview We need a mobile application + admin dashboard similar to Pay & Lock — a platform that allows retailers to manage customer EMI payments, automate reminders, track payments, and secure phones sold on installments by locking/unlocking based on payment status. The system should also provide analytics and secure transactions. 1. Mobile Application (Android & iOS) ... Main User Roles Retailer App/User App Customer App Admin Panel access via Web Dashboard App Features Authentication Retailer / customer login & registration OTP / Email + Password authentication .. Customer Device Enrollment (EMI Tracking) Register customer devices with IMEI/Serial number Assign EMI schedule (installment dates & amounts) Auto reminders for upcoming payments ... Payment Management Integrate payments (UPI/Wallet/Card) Real-time payment status update Payment history and receipts Push notifications for successful / failed payments .. Device Security & Control Lock device if EMI is overdue Unlock device after payments Secure lock mechanism that survives restart / factory reset prevention Optional GPS tracking (location log) Offline & online locking options .. Reminder & Alerts Intelligent reminders (SMS / push notifications) EMI due alerts Permanent missed payment alerts .. Multimedia Features Audio reminders Audio message display when device is locked .. Profile & Settings Manage contact info Manage notification settings .. Analytics & Reporting Total payments received Outstanding payments Device lock/unlock history .. 2. Web Admin Dashboard Secure Admin Panel for Operations Retailer / Super Admin sign in Manage registered retailers Create/Edit/delete EMI plans Dashboard: analytics, revenue graphs, device status Manage payment gateways Send mass reminders Customer support panel Admin Features View registered customers & devices Force lock/unlock devices Issue refunds / handle disputes Export reports (CSV / XLS) .. 3. Backend / Server Requirements RESTful API Secure authentication (JWT/Token) Database (PostgreSQL / MySQL / MongoDB) Push notification service (Firebase or similar) Real-time updates Security Device lock should not be bypassable by normal reset Data encrypted in transit and at rest Strong privacy features ..4. Payment Integrations UPI Payment APIs (Google Pay, PhonePe, Paytm) Card/Bank integration Support for recurring payments (EMI) Webhooks to update payment status ..5. Reports & Analytics Dashboard & reports for: Completed / Pending payments Lock / Unlock activity Customer repayment trends Retailer performance ... 6. User Experience Requirements Clean & intuitive UI/UX Multi-language support (optional) Offline Mode where possible Fast navigation ... 7. Platforms Platform Requirement Android App Yes (Primary) iOS App Optional / future Web Dashboard Yes .. 8. Security & Compliance App lock security Protection from tampering PCI-compliant payment safeguards Data privacy & user consent ..... Technology Stack Suggestions Frontend (Mobile): Flutter / React Native (for cross-platform) Backend: Node.js / Python / Laravel Database: MongoDB / MySQL Push Notifications: Firebase Payment Gateway: Razorpay / Stripe / UPI integrations Hosting: AWS / Azure / Google Cloud Deliverables ✔️ Fully functional Android (and optional iOS) app ✔️ Web admin dashboard ✔️ Backend API + database ✔️ Payment gateway integration ✔️ Documentation & source code ✔️ Deployment support & maintenance option