Multi-Store Grocery Delivery App

I'm seeking an experienced developer to create a comprehensive grocery delivery app similar to Zomato. The app should include:

Key Features:
- User login & registration
- Real-time order tracking
- In-app payment system

Delivery Services:
- Scheduled delivery
- Express delivery
- Store pickup

Integration:
- Must integrate with multiple existing grocery stores

Ideal Skills & Experience:
- Proven experience in developing delivery apps
- Strong knowledge of payment gateway integration
- Expertise in real-time tracking systems
- Experience with multi-store integration

Please provide examples of similar projects you've completed and your approach to this development.