I remembered I had downloaded this application a while back and finally took the time to check it out and take some measurements of a model I am working on in Blender. XgoldenSection ran smoothly and was easy to position and manipulate but strangely hides information such as the coordinates of the center and end points and angle measure in a tab in preferences. It does continue to update this data if you adjust the ruler on screen with the prefs window open but this seems a really odd design choice. Other options include overlaying various circles, customize the color/width of lines, displaying guides, and locking it to X/Y adjustments only. I didn't have any crashes or other obvious bugs while I used it for a couple hours.
It has a 14 day trial but I don't know if it is quite worth the $13 asking price due to it hiding the measurement data. I'd throw down $8 - $10 right now for the feature set. If the dev made the display of angles and measures toggle like the display of circles around the points I'd be more inclined to consider $13 because there would be no need or temptation really to use PixelStick or another screen ruler tool.