Screen Off locks your device without using the Power Button and allows unlocking with a Fingerprint. This App puts your device in true Standby unlike some similar apps that will only turn your screen black causing battery drainage.

This is a free trial you can buy the full app after closing the advertisement.

This app uses the new Accessibility Service found in Android 9 Pie but for older version of android this app uses the Device Administrator permission.

How to remove on Android 8 or lower:
Go to Android Settings -> Security -> Device Administrators -> Deselect Screen Off -> Uninstall