Oneclick ForceStop for Android
It can take several minutes but it will indeed kill everything including running foreground apps. Five stars for being the one and ONLY app that does this minus two stars for taking so incredibly long that it essentially hangs the phone (though you can interrupt it)
Force stops all google apps like, YouTube, google+, keep, maps, every google app... Thus making your device faster and battery efficient.. Really love it
Dont work
I've tested dozens of task killers and this could possibly be the most powerful one out there right now. Anti-Virus, data monitor, call blocker, etc., everything got killed! (Might take 2-3 minutes though.) However, it badly needs to give users the option to whitelist apps (not necessarily Google apps!), or to kill only the foreground (non-responsive) app. At present it's like the Hulk on a rampage killing friends & foes alike - a mass destructive weapon that badly needs taming. Moreover, after killing, it turned off all apps (NoLED, Elixir, full!screen) that was set to be on in Accessibility! You might also find a widget or two needs to be reinstalled, or certain apps that were meant to autostart do not anymore. On my phone it even reset the settings I've made with my faux123 custom kernel!! Surely users don't want that!!!!
by U####:
With root, says done, nothing killed.