This is an app that displays the battery level on the screen and also indicates the battery level by displaying a notch around the camera lens. You can set the notch width and height to the exact value you need. You can also customize the colors of the battery level indicator. You can set it to be displayed when the screen is on or off. 

The app does not monitor or collect any data regarding the usage of the device.

You can set the level to display on your lock screen. This is especially useful for people who have a disability to read numbers and work better with visual data.