LearnDash offers a variety of add-ons that can extend the functionality of your online courses. Some popular add-ons include WooCommerce, which allows you to sell your courses and process payments through your WordPress site, and Gravity Forms, which allows you to create custom registration and enrollment forms. Other add-ons include integration with popular webinar platforms like Zoom and GoToWebinar, as well as integration with social media platforms like Facebook and Twitter. LearnDash also offers add-ons for advanced quizzing and reporting, gamification, and course content protection. With these add-ons, you can customize your online courses to meet your specific needs and provide your students with a more engaging and effective learning experience.