Sprightly Software (http://www.sprightly.ca/) has released Screen Ruler 2.1 for Mac OS X, an update to the utility for working with on-screen graphics. In the upgrade, ruler graphics for the box measurement tool now display measurement increments appropriate to the selected unit, and other bug fixes.
Screen Ruler includes four tools including box and line measurement tools for making measurements, a color picker for determining the exact color of a pixel, and a grab image tool for making screenshot selections. It sports keyboard shortcuts for initiating measurements, picking a color, taking screenshots, and copying width, height, length, color, and image data.
Screen Ruler is compatible with Mac OS X 10.6 and higher. It sells for US$9.99 and is available worldwide exclusively through the Mac App Store in the Graphics & Design category.