Screen Ruler - Coin Calibrated

This is the first screen ruler in the android market that can be easily calibrated using a coin as a reference. Phones and tablets from different manufacturers have different screen sizes and dots per inch (DPI) resolutions. A ruler app has to be calibrated to give accurate measurements. Unfortunately, most ruler apps in the Android market have no calibration functions, or need to be calibrated with a ruler. But, if I have a real ruler, why do I need a phone ruler?

With this coin-calibrated screen ruler, you won't need to worry about the phone model, screen size, or screen DPI of your device. As long as you can find a coin in your pocket, or in your car's coin holder, you can easily calibrate this ruler and make accurate measurements!

Calibration takes less than 10 seconds, and you only need to calibrate your device for once. In the current version, this Coin-Calibrated Screen Ruler supports coins of US dollar, Euro, Chinese RMB, Japanese Yen, and Canadian dollar.