The new version of the tool is now avalable for download here:http://wonderwebware.com/screen-ruler/ 

Yes, the new version of screen ruler has been published with important customization options added and with every new version this toy becomes better, in my opinion. There are a lot of feature requests in the forum, so there will be future development, but I have to work on the other tools too, so (as usually) I cannot say when the next revision will become available…

More info here: http://wonderwebware.com/screen-ruler/