Screen Ruler Pro was made for one single purpose -- to be the best screen ruler out there. The tool is highly configurable and comes with different useful options (just some of them listed below):

* measure in pixels, millimeters, centimeters, points, inches

* define your own units

* horizontal and vertical guides

* customizable colors and translucency

* customizable tickers and direction

* rotation and "diagonal" measurement supported

* use figures to measure area and perimeter

* works with multi-display systems

* customizable ppi settings (incl. "screen calibration")

* works on Windows and Mac

• JR Screen Ruler 1.4
  The JR Screen Ruler is a great tool that allows you to accurately measure anything on your screen. This is especially useful when measuring graphics, web page browser sizes or...

• JR Screen Ruler Pro 3.1
  The JR Screen Ruler is a great tool that allows you to accurately measure anything on your screen

• A Ruler for Windows 1.0.5
  A Ruler for Windows is a free on-screen pixel ruler for your PC. It provides you your choice between a rich woodgrain ruler, or at the touch of a button, a clear see-through plastic ruler. With A Ruler for Windows you can use your screen normally...

• Onde Screen Rulers for Mac 1.12.16
  Onde screen rulers is a online measuring tool to measure dimensions of any objects in pixels, inches, centimeters, picas and measure angles in radians or degrees on Mac

• Universal Desktop Ruler 3.4
  It allows you to measure not only a straight line distance but any curved distance on the Screen

• Ruler By George! 1.3
  Ruler By George! is a handy virtual ruler ready to be dragged around on your computer screen; it's very useful for measuring graphic objects in pixels, inches, and centimeters

• Philer Ruler PRO 2.1
  Philer Ruler PRO - is a professional virtual ruler for your computer

• Desktop Ruler 3.28
  A Virtual ruler - very useful with spreadsheets, graphic utilities and programming tools