Ruler

A simple, but very handy on screen ruler.

https://www.keuwl.com/apps/025ruler/

Should work on devices from Android 4.1 (Jelly Bean) & upwards. App Version 1.08. Ad Free. Privacy policy

App summary:
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.