1)   Screen Compass 4.0 The Screen Compass allows you to measure the radius, circumference and area of circular or polygonal shapes on your screen simply and quickly. The Screen Compass floats above any other application so you can measure any angle on your screen. 2)   Screen Compass Mac Edition 3.2 The Screen Compass allows you to measure the radius, circumference and area of circular or polygonal shapes on your screen simply and quickly. The perfect compliment to the Screen Calipers and Screen Protractor, the Compass is simple and easy to use.