Tutoring Platform Android App Development

I'm looking for an experienced Android developer to build a fully functional tutoring platform app. The app should connect students with tutors for both online and offline sessions.

Key requirements:
- User Roles: Student, Tutor, Admin
- Core Features (essential): Please suggest based on your expertise
- User-friendly interface
- Secure payment integration
- Robust backend to support real-time data

Ideal skills and experience:
- Proficiency in Android app development
- Experience with real-time chat and booking systems
- Strong UI/UX design skills
- Knowledge of secure payment gateways

Please include your portfolio and relevant experience in your bids.