A free program for Android, by Masaru.

Screen Tools is a utility app that provides a set of useful tools for the display of a device. It provides a function to filter the display of the device to change the brightness, contrast, color, etc. It is useful for people who want to prevent others from seeing their applications, photos, contacts, and other important information.

The function to filter the display of the device can be applied to all applications, not just the ones that you want to show on the screen. It is also useful to hide private information, such as photos, videos, contacts, and messages.

The function to change the brightness, contrast, color, etc. is useful for people who want to change the appearance of the display.