[maaark]

I prefer Twilight, it has adjustable color temperature, as well as scheduling based on time of day or sunrise/sunset.

Both have paid versions, but Bluelight Filter's constant nagging & promotion of their other apps made the choice easy for me.

[stephengillie]

I used Twilight for month, but I found the red tint made my phone hard to read, so I kept disabling it. I still get the same 6-8 hours of sleep as I usually did. I may not be susceptible to the blue light impact on melatonin as I've been using screens from wake to sleep for over a decade.