As you may already know, an AMOLED display differs from the LCD variety in that its blacks are darker. This is created by nearly turning off or completely turning off the pixel when it is assigned to the color black. In turn, the parts of the screen displaying “black” use much less if any power, which theoretically creates better battery life.
With Pixel OFF, users of AMOLED devices can reduce their power consumption by overlaying a mesh of evenly spaced black pixels on their displays. The app is free, but a $1.68 in-app purchase will unlock other filters. It does not require root and can be started with the phone or activated at a certain battery level.
 
Chrome with the default mesh of Pixel OFF not active (top) and active.
According to AndroidPolice, reviews of Pixel OFF are positive. One user explained that he or she got “16 hours on-time with just 28% battery life.” Although, the tested device and the screen brightness are not known. It’s probably a good idea to test the app and see if it is better than turning the brightness down before considering the in-app purchase.
[pb-app-box pname=’pl.poveu.pixelbatterysaver’ name=’Pixel Battery Saver Booster’ theme=’discover’ lang=’en’]
https://play.google.com/store/apps/details?id=com.urysoft.pixelfilter
Pixel OFF Save Battery AMOLED
Saves battery by applying a filter that turns off pixels of AMOLED screens.
AMOLED screens doesn’t have a backlight at all. Instead, each little sub-pixel is like a tiny red, blue, or green colored light. If the screen is instructed to display black, it doesn’t need to block any light, it simply doesn’t light up any of the little colored sub-pixels.
Black pixels save you a lot of power because those pixels can be turned completely off. There is a relationship between brightness and power, but to really save juice you need a true black.
https://play.google.com/store/apps/details?id=com.urysoft.pixelfilter