Actually ipad have uploaded different courses' sound clips from various high-ranked universities
If you have it, you can also take a look...(However, they are required to install be4 listen..)
BTW, there is 1 course from coursera I am interested
The introduction to Astronomy
When I was studying in college, I have already noticed.
However, impossible to squeeze out extra time to revision this new course, I quit this course...
Now, there is no marks hindering me, I can listen it when I have time.