Cross-Platform Retail Shopping App

I'm seeking an experienced mobile app developer to create a retail shopping app for both iOS and Android platforms.

Key Features:
- Payment Integration: Secure payment gateway.
- Product Search: Advanced search functionality.
- User Reviews: Customer feedback section.

Ideal Skills and Experience:
- Expertise in developing cross-platform mobile apps.
- Strong background in payment integration.
- Experience with UI/UX design for seamless navigation.
- Ability to implement robust review systems.

Please provide samples of previous work and include your approach to ensuring app security and user data protection.