Course completed page
There should be a proper endpoint for a course. When you finish the last lesson you should be taken to a screen where it says congratulations you have now finished this course. And an option to download their certificate.
I have added several courses to my test site and completed them and I also agree there should be a completed message or page.
Each time I finished the final lesson of a course you are just left in limbo...
This would make the user experience much more complete.
I second this. This would also be a good place to download the certificate and ask for review.