Cross-Platform Shopping App Development

I'm looking for an experienced app developer to create a shopping application for both iOS and Android platforms. The app will feature physical goods and include an item catalog and cart payment functionality.

Key requirements:
- User-friendly interface
- Secure payment integration
- Robust item catalog
- Both platforms compatibility

Ideal skills and experience:
- Proven app development experience
- Expertise in payment gateways
- Strong UI/UX design skills
- Experience with both iOS and Android platforms

Please include your relevant experience in your application.