Professional Skills Education App Development

I need an education application focused on offering online professional skills courses. The primary purpose is to enable users to access and enroll in courses that enhance their professional capabilities.

Key features should include:

- User-friendly interface for course navigation
- Secure payment gateway for course purchases
- Progress tracking and analytics for users
- Interactive elements like quizzes and discussion forums

Ideal candidates should have experience in:

- Mobile and web app development
- UI/UX design
- Integrating secure payment systems
- Implementing progress tracking systems

Experience in developing educational platforms is a plus. Please provide a portfolio with relevant work.