When looking at something in macOS, how can I put some kind of horizontal line so that I don't forget my position on the screen?
Let's say I'm reading a list shown on the screen, and I've mentally processing the bottom quarter of the list, so I want to put a marker there so that when I come back from lunch I know where I need to resume from.
My ad hoc solution so far has been to position a Finder window at the point where my region starts. But I end up using Finder for other tasks and can easily loose my "bookmark".