I got in over my head in trying to remove duplicate icons from the App drawer, so I elected to do a reformat and start anew. Marshmellow 6.0 loaded without cause. I commenced configuring the phone starting with Settings/ Wi-Fi and working my way down.. When I got to 'Apps' and tapped it, it brought me to the Apps screen and showed me all the installed apps. In the previous install of 6.0, when I tapped the loaded apps screen, I got a small drop down that showed, IIRC, All-Enable-Disable. In this recent install of 6.0, that drop down is no where to be found. What I now have in the upper right hand corner, is a 'Settings' icon and the three vertical dot icon. Tapping the Settings icon brings me to a 'Configuration' page. Tapping the dots icon brings me to a drop down for 'Show System' and 'Reset preferences'. No where to be found is the 'Disable-Enable' option.
What I am trying to accomplish is reduced battery drain when the phone is idle. Would the app Greenify accomplish the same objective? Still mystified why the 'Disable-Enable' drop down will not appear.