Comprehensive e-Learning Mobile App Development

I'm looking for a seasoned developer to help build a two-sided, secure, interactive, and comprehensive educational mobile app platform for online courses. This platform will need to support both iOS and Android. Key features: - Course categorization across Subject Matter, Difficulty Level and Instructor. - Robust search functionality by course or instructor. - Seamless hosting of webinars. - User roles for Students, Instructors, and Administrators. - Interactive elements such as live chats and quizzes. Ideal candidates will have: - A strong portfolio of e-learning platform development. - Profound understanding of secure coding practices. - Proven track record of implementing interactive features. Please include relevant examples of similar projects you've executed in your proposal.