Originally Posted by AndroidDeveloperLB
1. Doesn't it mean that it uses CPU all the time while the screen is on
Not very much. It doesn't even show in my S4's battery stats. Just did a test and ran piece of code responsible of identifying topmost app as many times as it would run if you had your screen on 24h. Longest run was under 2 minutes tested it on Galaxy S, Galaxy Nexus and Galaxy S4. Of course system will take some time of it's own when it's switching from process to process, but haven't seen any battery drain.
2. Doesn't it mean there is a delay between the time you go to an app and the time that the settings apply?
Maximum of 1.5 seconds, so it feels pretty smooth.
3. What happens when there are multiple apps running on front, like those with floating stuff (AirCalc for example), and the multi-window feature apps (as used on Samsung devices) ?
I have tested Samsungs multi-windowing one time and it reports program you last touched to be topmost, so it's settings are applied.
Also, BTW, the link on the first post isn't clickable.
I don't have enough posts to link outside xda.
I also have a suggestion: please allow GPS enable/disable, so that when I open Waze it will be enabled, and when I close it, it will close it.
I know it was possible via a hack, but now it's possible using root, as used on "Condi" app.
That's the most requested feature. I will start looking how to implement it after few simpler functions.