Health Services Delivery App

I'm looking for a ready-made health booking and services delivery app specifically for Android.

Core Features:
- Appointment Booking
- Health Services Catalog
- Service Delivery Tracking

Additional Features:
- Payment Gateway Integration
- User Reviews and Ratings
- Push Notifications

Ideal Skills and Experience:
- Experience in mobile app development, particularly on Android
- Familiarity with integrating payment gateways
- Ability to implement user review systems and push notifications
- Prior work on health or service delivery apps is a plus

Please provide a demo or screenshots of the existing app.