Flutter Developer for Intercity Carpooling App Customization (Firebase & Seat-Map Selector)

Project Overview: We are looking for a talented, independent Flutter developer to customize a licensed Intercity Carpooling template: "Public/Commercial License of PoolMate - BlaBlaCar Clone" from CodeCanyon. This is a targeted development project with clear deliverables and a fixed timeline. We provide full translator support for the project requirements. Key Custom App Logic to Implement: 1. Core Framework and Multi-Branding: Built on top of PoolMate's native cross-platform Flutter framework and its existing Firebase/Firestore backend setup. Crucial Requirement: The developer must deploy TWO SEPARATE apps (App A and App B) using this SINGLE source code. Both apps will connect to the exact same Firebase database but must be packaged as two separate applications with different app names, different package IDs, different colors, and different brand logos. The app will be localized for a foreign market, supporting the foreign language and foreign currency. 2. NO Real-Time Location Tracking: To eliminate ongoing server/API costs, we DO NOT require live GPS tracking or map-matching for moving vehicles. The app functions strictly as an intercity matchmaking and seat-booking directory for specific routes. 3. Custom Visual Seat-Map Selection: Replace PoolMate's standard seat-quantity counter stepper with a custom visual seat-map layout grid. The app must support specific vehicle grid configurations: Sedan, SUV 4 seat, SUV 5 seat, SUV 6 seat, SUV 7 seat, MPV 7 seat, MPV 8 seat, and more. Additional seat configurations may be identified and required during development. Passengers must be able to tap and reserve a specific seat. "RideKit" UI screens can be used as a design reference only. 4. Hybrid Seating Pricing: The Admin Web Panel will set a "Minimum Base Fare" per route to prevent underpricing. On top of that minimum base, the driver has full control to manually input custom specific prices for each individual seat on their selected vehicle layout grid (e.g., pricing the front VIP seat higher in the foreign currency). 5. Pre-Paid Wallet with Atomic Concurrency and Feature Toggle: Utilize PoolMate's built-in driver wallet framework (Manual admin top-up approval for MVP stage). Crucial Requirement: The booking and commission deduction logic must use strict Firestore transaction-based concurrency control to prevent duplicate seat reservations. The transaction must atomically read seat availability, verify that the driver's wallet balance is higher than or equal to the platform commission, deduct the commission, and commit the booking. The Admin Panel must include a simple Feature Toggle Switch to turn the escrow deposit payment module ON or OFF dynamically without changing code. 6. Conditional Cancellation/Refund Logic: If a passenger cancels a confirmed booking before a defined cancellation deadline, the exact platform commission is automatically refunded back to the driver's wallet exactly once. No commission refunds allowed after the deadline. 7. IP Ownership & Bug-Fix Support: 100% of the modified source code and intellectual property of BOTH configured apps belongs entirely to our company (Work-for-Hire agreement). Deployment of both apps must be on our official corporate Apple and Google Play Console developer accounts. Includes a mandatory 30-day post-launch free bug-fix window. Project Fixed-Price Milestones (Total MVP Budget: up to 45,000 INR based on experience): - Milestone 0: Technical Source Code Audit. Environment setup and successful template build deployment. Developer must inspect the database architecture before moving forward. - Milestone 1: Visual Seat Layout System supporting Sedan, SUV 4 seat, SUV 5 seat, SUV 6 seat, SUV 7 seat, MPV 7 seat, MPV 8 seat, and other custom grids with custom price injection linked to Firestore. - Milestone 2: Admin Web Panel configurations (Route minimum floor price, manual wallet top-up approval, and Escrow payment Feature Toggle Switch). - Milestone 3: Wallet deduction system with strict Firestore transaction safety, insufficient balance protection, and cancellation refund logic. - Milestone 4: Multi-device concurrency acceptance testing (simultaneous duplicate booking stress tests), final bug fixes, and deployment of BOTH separate branded applications to our corporate Google Play Store and Apple App Store developer accounts. Developer Requirements: - Expert proficiency in Flutter, Dart, Firebase, and Firestore transaction logic. - Experience implementing custom visual grids (GridView/CustomPainter).