I have been thinking about the simplest, quickest way to tutor online. It might be some adaption of what I have been doing 1-on-1, face to face. There would usually be some problem that couldn't be worked out in the tutoring session, so I would go home and write out the solution on paper (using pencil), scan it into my computer, put it in OneDrive and send my tutee a link. Anything else took too long.