Multi-Platform Device Trade & Repair App

I need a comprehensive platform, similar to Cashify, that allows users to sell old devices, buy refurbished ones, and book repair services. The system should include:

Customer Website & Mobile App (Android & iOS):
- Sell old devices
- Buy refurbished devices
- Book repair services
- Verify device condition and price
- Schedule pickup and track orders

Admin Panel:
- User management
- Order management
- Pricing and inventory control

Partner/Technician App

Core Backend:
- Robust pricing engine
- Efficient logistics system

Ideal Skills & Experience:
- Experience in developing multi-platform apps
- Strong backend development skills
- Familiarity with admin panel functionalities
- Knowledge in logistics and pricing engines

Please provide samples of similar work.