WonderWebware.com Screen Ruler is the only name that you can trust, if you are looking to measure the size of any application or object on the screen.
The accurate tool useful to measure any item on the screen with accuracy and perfection. The tool is capable in measuring almost any item on the screen, whether it is the size of diagrams, or the distance between two points with much ease just by placing the scale over it. The features supporting this tool are: ability to measure in pixels, millimeters and centimeters; supports the horizontal and vertical guides, customizable translucency, tickers are also customizable, stay on top option to keep the application floating over the Windows, includes screen edges snapping, ability to remember last state, position or options; includes mouse and keyboard moving/resizing, and much more.
WonderWebware.com Screen Ruler is a configurable tool for perfect measurements of anything on your screen.