It would be good if it had a function to limit brightness by time or by battery level and was Foss (but being Foss is not necessary if app is good and don't want too much permissions). Current screens are too bright for me.
I use Night Owl. It has a setting for time, but not battery level. You can set it between 0 - 100%, but 100 isn't "completely black". It defaults the brightness to minimum for the phone when it is on and goes further.