How to go to the previously viewed page in various PDF viewers, e.g TexWorks'?

I only use Okular, which has shortcuts and toolbar buttons for "back" and "forward" navigation. The predefined shortcuts seem to be Alt+Shift+Left / Alt+Shift+Right, but you can always redefine them.

In evince (a Gnome PDF viewer apparently), I found that there was no Back button by default, but you just have to right-click on the toolbar area, and a toolbar settings menu comes up. You click on that and then drag a Back button to the toolbar area.

In operation, you click on this Back button in evince, and it gives a menu of all of the previous pages you have visited, in reverse order. So you can click on the top page number to go back one step, and so forth.