The Great Courses Plus is a streaming version of the Great Courses, both of which are offered by The Teaching Company.
However, each service uses its own website, and the course page on The Great Courses Plus doesn't contain as detailed of a description as the corresponding one on The Great Courses.
So this simple extension simply adds a new button to each course on the Great Courses Plus if a corresponding page exists on The Great Courses website, so you can get more information on the course.
FYI this extension was written as a part of a blog series on computer programmng. Please see the original blog post here: