Do those battery saver apps really do their job?

[yshysh]

I've tried meticulously a variety of android battery saver apps and task manager apps on my old HTC one. Although all those apps claimed to save my battery power, but really? Tried very hard to turn on and off some process using those apps. And in the end, I still have to charge my phone when evening is coming. So the question, do those apps really do the job?

Maybe I didn't find the right app. Please share your experience

 

[MikeCorsten]

I have installed the Doze app on my fiancee's Galaxy S4 and it has truly worked saving her battery when it's not in use.