Convenient for the flip type cover.
When dark colors, such as black and brown, are being used with flip covers, such as Galaxy Note, a proximity sensor may not react.
In that case, it may be improvable if the sticker of white or a bright color, etc. are stuck on the portion in contact with the proximity sensor (upper part of a screen) of a flip cover.
This application is using DeviceAdministrator.
So it is necessary to cancel at the time of uninstallation.
(Other settings => Disable DeviceAdmin)