"Add courses to your profile from our catalog"
I'd need to see these before signing up. The picture of the books on the shelf seems to imply you can use MOOCs from popular sites but "our catalog" sounds proprietary.
This is something I can add. Our catalog currently consists of all courses from Coursera, edX, Udacity, Udemy, and The Great Courses! Maybe I should also fix that wording as well.
Ahh I see. Then I would use something closer to what you just wrote there:
Works with Coursera, EdX, Udacity, The Great Courses, and Udemy courses.
I'd actually recommend changing the tagline on the site, as well, to be more clear: "Find the perfect study buddy for all your Coursera, EdX, and Udacity courses."
Our catalog currently consists of all courses from Coursera, edX, Udacity, Udemy, and The Great Courses
Just put that sentence on your site.
It would also be helpful to see "class sizes" for a given course. I don't want to sign up only to find after the fact that nobody is taking the same course as me.