Cross-Platform E-Commerce App Development

I'm looking for an experienced developer to create an e-commerce app for both iOS and Android platforms. The app will primarily sell physical goods.

Essential features include:
- User accounts
- Payment gateway
- Product reviews
- Service charges
- Vendor management

Ideal skills and experience:
- Proven track record in building cross-platform e-commerce apps
- Strong knowledge of mobile UI/UX design
- Experience with secure payment integration
- Familiarity with backend services for user accounts and vendor management

Please provide your portfolios and relevant project experience.