Closing apps when locking screen (root)

Hi everyone!
I'm using a Samsung Galaxy s6 with SuperSu. Rooted. I've tried to find an app that will close all apps when I lock the screen, but so far i haven't been able to find one that actually works. There is at least one I know that would do this for me, DU Battery Saver Pro, but it does not ask for root permission no matter what I do, so it won't work. Do you guys know any that would work?

Thanks

 

I have noticed if it doesn't ask for root access it can't do the jobs that require root (auto close apps, auto turn off data, etc). I have noticed apps like skype will always stay awake and leech my battery, even if I close it or force stop, it will just start again right away. It was not possible to close skype prior to rooting because it is a system app on S6, now I can use apps to close it. It will save me from a lot of battery drain if I'll be able to close certain apps automaticly, namely Skype/facebook/messenger. These apps together probably use around 30% of my battery while I'm not even using them.

 

30% of all apps. I don't want these apps to run and at the end of the day see that they have taken a big chunk out of my battery even though I haven't used them at all. I want to use my phone like a computer, if I want to check facebook or messenger I go onto it, and then close it. 0% battery drain after that.

 

Hey thanks for your reply. I still haven't gotten Marshmallow yet.

I'm aware that some apps will start up again immediately if you try close them.
I've been trying Greenify a little, however I haven't been able to install Xposed Framework yet.

The experimental feature "Greenifying system apps" : Deprive system apps of immunity to hibernation, make most of them greenifiable. This sounds like what I am after. It's working very well with the other non system apps, I've disabled facebook, skype and messenger, added some other apps and I'm now getting way better battery life, I think it'd last 3-4 days like this instead of 20 hours.

So yeah, I am looking forward to getting Marshmallow since I heard it has this feature.
The problem for me is that these system apps are immune(even with root access), you can't really touch them, they just pop up right away if you close them, I haven't found apps that can deal with that except maybe greenify with exposed.

I've never had syncing on, but notifications, yeah..