Lumen - magic auto brightness based on screen contents. You control Lumen simply by using your brightness keys - it'll automatically learn your preferences.

Twilight is described as 'The app filters the blue spectrum on your phone or tablet after sunset and protects your eyes with a red filter. The filter intensity is smoothly adjusted to the sun cycle based on your local sunset and sunrise times' and is a popular color temperature tool in the system & hardware category. There are more than 25 alternatives to Twilight for a variety of platforms, including Windows, Linux, Mac, Android and Wayland apps. The best Twilight alternative is f.lux, which is free. Other great apps like Twilight are Redshift, LightBulb, Red Moon and RedshiftGUI.
Lumen - magic auto brightness based on screen contents. You control Lumen simply by using your brightness keys - it'll automatically learn your preferences.

Night Screen is created for those people who spend a lot of time at night working.
Limit your exposure to energy-efficient lighting before bed. In addition to the LED screens in your electronics, energy-efficient lighting emits a lot of blue light.




This advanced Windows app allows you to alter the screen shading according to the time of day, which is great if you work outside the normal hours, or if you need a lift in the afternoon. You can set the colour tints and your awake and sleep times.

"JBlueCut" is a blue light screen filter - eye protection App. Can effectively reduce the bluelight on screen and ease eyestrain by few simple steps.

Shifty was made to expand the capabilities of the built in Night Shift feature in macOS. You can disable Night Shift for specific apps and custom time periods. It also provides easy access to a slider to fine tune your color temperature.



FireLux is the most popular Web-based alternative to Twilight.
Setting the color temp of the screen really only requires about 40 lines of C (80 or so all inclusive). sct is a crude utility which does roughly that. I’d say exactly that, but some of the calculations aren’t actually exact.
Shady puts a shade over your screen to help soothe your tired or dazzled eyes. You can use it to reduce your Mac's brightness far below the usual minimum, without any risk of damage to your screen.



A Python program that calculates ambient brightness and sets screen's correct backlight using a camera.

Small GTK GUI application to set contrast, brightness and gamma for wayland compositors which support the wlr-gamma-control protocol extension. Basically this is the example from here: https://github.com/swaywm/wlroots/blob/master/examples/gamma-control.

it can reduce screen brightness. as far as i know f.lux can not reduce screen brightness.