Cross-Platform Grocery Delivery App

I'm looking for an experienced mobile app developer to create a grocery delivery app that works on both iOS and Android. The app should include:

- User registration and login
- Search and browse products
- Order tracking
- Payment integration with various payment options

Ideal skills and experience:
- Proficiency in developing cross-platform apps
- Experience with payment gateway integration
- Strong UI/UX design skills
- Familiarity with backend development to manage user data and orders

Please provide examples of similar apps you've built.