Here is an easy-to-use screen ruler application that allows you to accurately measure short lengths in cm or inches. This measuring tool (portrait orientation, Android 6 or newer) works on most tablets, phones and smartphones, regardless of their screen size or of their connection to the Internet. However, a bigger screen size offers higher resolution and a better view of the divisions.

How it works

This application automatically detects on start the size of your screen and displays the ruler divisions accordingly. However, if you are not sure about its accuracy, the Calibration function offers the possibility to adjust the divisions by comparison to a standard ruler. The correction factor can be restored to 1.000 at any moment by tapping Reset. To measure the length of an object, place it near or on the screen (be careful to not scratch your screen) and adjust its position exactly to the bottom edge. Then look perpendicularly to the screen and read the first division not covered by the object. This process is easier if one or two sliders are selected; in the latter case, the measurement should be considered between the central lines of the sliders.

Features:

-- two units of measurement can be selected, cm and inches
-- FREE application - NO ADS, no limitations
-- measurement of the length on the two long sides of the device
-- this app keeps the phone's screen on
-- easy measurements using two sliders with multitouch capability
-- three measurement modes
-- fraction or decimal inches
-- simple calibration process
-- up, down, left or right text orientation
-- text-to-speech (if your speech engine is set to English)