Study App Development

I'm looking for an experienced developer to create a study app and its corresponding website.

Core Features:
- Quizzes and assessments
- Video lessons
- Progress tracking
- Access payment options
- User login system

Ideal Skills:
- App and website development
- User authentication systems
- Payment gateway integration
- Experience with educational platforms

I would like a seamless, user-friendly experience. Please provide examples of similar work.