A simple, but very handy on screen Ruler. No Permissions, Free & No Ads. Automatically sizes to most screens. However, check scaling with a normal ruler on first use. If it is not correct, touch CAL and stretch the ruler to the correct size. Centimeters and inches. Measure length between two markers. Copy to clipboard.
Ruler is completely secure for downloading. This application was originally designed by keuwlsoft and it is included in the Tools category. The overall score for the app is 4.2 on Google Play.