Post [Q][ultra battery saving mode]

hello to all members of XDA ,
from what I have seen lately have come out super- smartphone which S5 , one M8 ... with lots of goodies both hardware and software . going to the point, I do not have the technical knowledge to do this thing, then I ask you, and anyone interested, in to help . I would like to create a useful app for all Android smartphone , allowing you to use both the S5 mode risparmiio energy that makes the screen black and white, grayscale , and together with this ultra power saving mode to one m8 , what opens one app at a time.
Now with regard to the energy saving mode of one m8 , there are some things I would like to emphasize :
- When this mode is active , you can open one app at a time
- If you already have one open , it will automatically close the task manager without having to do everything manually .

this would allow anyone with old Android smartphone to have enough energy , so much as to meet the requirement " means that arrival time at the end of the day no ifs , ands or buts ."

I repeat that my knowledge can not meet this demand , being a complicated app to fill out ( for me). I ask anyone interested to post everything here so as to avoid too many threads . if I posted in the wrong section , I apologize . Thank you all in advance!