Creating this list for my future reference; I have not personally investigated all of these.
My Slide Rule – Searches the web for courses in any topic
Scholars Online (Classical Christian)
HS College Bound – Shakespeare for High School credit. Also offers some high school planning courses.
College Admissions Essay class from Brave Writer
The Lukeion Project – Latin, Greek, and History and Literature related to the classical world. High School level. Fantastic, high quality classes and instructors.