Hello!
I guess adding a background image option to the help window is a nice feature. I'll add that to the backlog.
As for the click / touch support, I think that's a good idea as well, but I would like a feel more details before getting down into code. Since the window can be hidden, there won't be anything to click / touch to make it visible. What I think could be done is to add an overlay button to toggle its visibility. So clicking / touching on the button would hide or show the window. Is that what you were suggesting?