Ruler by E-Tech Blitz is a free ruler and tape measure app for Android devices running on Android 9.0 or later. With this app, you can measure the length or size of small objects in centimeters, inches, or millimeters. The app is designed to measure objects that fit into your device screen and it always works even when no stationary ruler is around.

The app has a simple and beautiful design with an easy-to-use calibration mode for accurate adjustment of the measuring length. It is already calibrated at the factory, but if that is not good enough, you can calibrate it using another ruler. You can measure the length on both sides of the screen at the same time, and the app offers measurement in decimal or fraction.

In addition to the ruler and tape measure features, Ruler also includes a simple calculator, an advanced calculator, and conversion tools for area, length, weight, and temperature.

Overall, Ruler by E-Tech Blitz is a convenient tool for measuring small objects on your Android device. It is easy to use and provides accurate measurements with just a few taps on your device screen.