Cross-Platform E-commerce App Development

I'm looking for a skilled app developer to create and publish an e-commerce app on both iOS and Android platforms. The app's primary purpose is to sell products or services.

Key requirements include:
- User-friendly interface
- Secure payment integration
- Product catalog display
- Search and filter functionality
- User account management
- Review and rating system

Experience in developing e-commerce apps and familiarity with both app stores' publishing processes is ideal. Please provide a portfolio with similar projects.