Many digital rulers allow you to drag lines or "calipers" with two fingers to lock in a specific measurement for easier reading.
Perfect for measuring small physical items like jewelry, screws, or coins by placing them directly on the screen. on screen ruler apk download
On-screen rulers are specialized utilities that display a digital scale—usually in and inches (in) —directly on your device’s display. Many digital rulers allow you to drag lines
If you are using a floating ruler, you must grant the app permission to "Draw over other apps" in your Android settings. Ruler - Measuring Tape, Inches - Apps on Google Play Inches - Apps on Google Play