- Eye protection
- Quick and easy adjustment of the screen dimming level
- Nice and simple interface
- Blue light filter
- Saves battery power (especially AMOLED)
- Low light (In bed, theatre, cinema, ..) usage for reading, browsing, texting or gaming
If it does not work on Xiaomi (MIUI):
Open Settings - All applications - Night screen - Manage permissions - "Allow access to pop-up windows".