Used Goods Mobile App Development

I'm looking for a skilled app developer who can help me create a mobile app for both iOS and Android. The primary purpose of this app is to facilitate the buying and selling of used objects.

Key Features:
- User-friendly interface for easy navigation
- Secure payment system
- Listing feature for sellers
- Search and filter options for buyers
- Chat system for buyer-seller communication
- Rating and review system
- Push notifications for updates

Ideal Skills:
- Proficient in cross-platform mobile app development
- Experience in e-commerce app development
- Knowledge of UI/UX design principles
- Familiarity with secure payment systems

Previous experience in developing similar apps will be highly regarded. Please provide a portfolio of your relevant work.