ScreenFilter (com.mjhdev.screenfilter) on Google Play
-Brightness setting - dim the screen below your phone's typical minimum brightness for a more comfortable experience in low-light settings and battery savings.-Red Hue setting - apply a red tint to your display to prevent the harsh blue wavelengths from damaging your eyes and disrupting your sleep patterns.-Disable Soft-Key backlight setting - disable the backlight for your phone's soft buttons. This only works for phones whose OEM hasn't explicitly overridden this setting.-Widgets - create widgets for your favorite configurations to enable and disable ScreenFilter with the tap of an icon!