For those who don’t bring physical rulers anywhere but seem to need them sometimes, On-screen Ruler is a great app to have. This handy, free utility app basically produces a floating ruler on your device’s screen, turning it into a measuring tool in seconds. You only need to grant permission for it to be displayed over other apps, then you’re good to go.

Developed by NeedJava, On-screen Ruler allows you to measure both tangible and intangible objects. You may use it to determine the size of the things on the screen or for objects you’re holding in your palms.

Handy and multipurpose ruler

A beneficial tool for UI testers or designers, On-screen Ruler helps users measure the elements on a screen accurately. Measurement units can be in centimeters or inches, and you can toggle between them through the settings menu. You can also slide the virtual ruler along the screen to determine a more customized end or starting point. Moreover, you can use it either vertically or horizontally.

You can also modify the color of the ruler’s measurements and hash marks. However, the color choices are super limited, even if you’re trying to type out a different color code, it eventually reverts back to the nearest built-in option. They may be limited but these colors must be enough for the ruler to be visible against backgrounds of any other color.

If you think that the ruler is showing inaccurate measurements, you can easily calibrate its settings. You can also drag it across the screen to satisfy any measuring necessity and it will adjust accordingly. However, the ruler shows only up to 16 centimeters and 6 inches. If you're measuring a relatively long object, this app may not be that helpful to you.

Is it worth using?

On-screen Ruler is a virtual measuring tool that anyone can use and understand. Should you come across a situation in which you need a measuring device, you can definitely go for this app. You may use it on its own or you can have it displayed over other apps, so you can measure certain objects there. The ruler's calibration, color, and orientation can all be modified.