PicPick version 3.1.6 is now available free of charge for private users. The paid version is available without advertising.
The PicPick Tools is a kind of collection of many useful tools including an Image Editor, Screen Capture, Color Picker, Color Palette, Magnifier, Pixel Ruler, Protractor, CrossHair and a Whtieboard to sketch ideas.
A complete overview of functions and a description can be found on this page http://www.picpick.org/features