Thanks, I've seen italki but [judging by https://www.italki.com/teacher/apply] it seems to focus on matching students to teachers who then can talk via Skype, while my question is more about services that replicate traditional teaching media. (recorded audio, video, printouts, perhaps whiteboard)

(Perhaps my question wasn't clear enough. My teacher is not yet looking for online students, just hoping to try some tools to see if it could work for him at all.)