Lux works really great if you have a Nexus 4. Instead of just overlaying a partially transparent block of color, it actually adjusts the screen temperature at a much lower level in the OS.
There is a Nexus 4 plugin on the Play Store to intsall if you want to try it out, made by the same developer.
After using Lux for a long time I've recently migrated to Velis autobrightness [1] and have, anecdotally, found it to work better. Less stochastic brightness changes, better bright and lowlight sensor attenuation and less batter drain.
