How to install this android app ?
On devices running Android 8.0 (API level 26) and higher, users must navigate to the Install unknown apps system settings screen to enable app installations from a particular location.
On devices running Android 7.1.1 (API level 25) and lower, users should enable the Unknown sources system setting, found in Settings > Security on their devices.
Note: After you installed the application, please disabled the installation from unknown source.