You can change the brightness of the display in the status bar .
black filter can under 0 % brightness .
this cut filter blue light and keep your eye health !
For More Info Google Play
Supported Android
{3.0 and UP}
Supported Android Version:-
Honeycomb (3.0–3.2.6)- Ice Cream Sandwich (4.0–4.0.4)- Jelly Bean(4.1–4.3.1)- KitKat (4.4–4.4.4)- Lollipop (5.0–5.0.2) or UP
Download Brightness controller PREMIUM 2.7.1 APK For Android