Developer's description:The Screen Protractor allows you to easily and quickly measure any angle on the screen to the nearest Degree or Radian. This perfect compliment to the Screen Calipers, the Protractor is simple and easy to use with any program. The uses of the Protractor are many and varied, here are just a few: - Engineering: measure blueprints and plans. - Design: measure any designs and photos. - Mathematics and Physics Education: allow students to measure onscreen in degrees and radians. - Cartography: measure bearings and overlay any mapping software or images. - Microscopy: measure tiny biological forms. - Criminology: accurately detect angles from crime scene photos. You may download the feature limited trial, and evaluate the Screen Protractor for as long as you need to. By purchasing the full version you can unlock the software to measure the full 360 degrees, and use the advanced features. - Easily measure any angle on the screen - Use keyboard controls to measure precisely - Measure in degrees, radians or five other units - Change the transparency to see through the Protractor to what you're measuring - 30 day money back guarantee The Units menu allows you to choose a new unit from the list of predefined units. The Protractor comes with the following pre-defined units: Degrees, Radians, Revolutions, Grads, Mils, Minutes, Seconds, and Bearings. You may also configure your own Custom Units using the 'Configure Units' menu option. Choosing this option will bring up a screen which allows you to choose a Custom Unit, rename and set the scale. You may also set the zero point, enabling easy relative angles to be calculated. The Protractor has a fully 'skinnable' interface. This means that you may download new skins and change the user interface. From aesthetic to technical you should find onscreen solution that suits your needs. Whatever you're measuring, the accurate solution at any angle, is the Screen Protractor.