Download Flux for FREE
If you have concerns over blue light from your computer affecting your sleep and health then this download is great! It makes the colour of your computer's display adapt to the time of day, warm at night and like sunlight during the day.
I've been using this for a while now and think it's fab, it automatically selects the correct colour for your display depending on where you are and time of day or night. So much nicer on your eyes, and can be temporarily turned off if needs be, such as if you are doing photo editing or something where true colour is essential.