Here i used a module ka "gravity box". And I changed the double tap home key to application launcher then selected 12 apps, and then i used floating shortcuts to make the apps float into windows. On another note, the gravity box kitkat module has various mods working for sprints mega 6.3, and here is a screen shot of the following type up.

Also if you close the floating window it's available to relaunch as a recent app selection and restores exact position you backed out at. For example, im in chrome i launch a floating window app, then i hit the home key and go into a message app, then i hold the home key until recent apps shows finally select the floating app; and done. You are right where you left in a floating window. So with this kind of behavior it's easier for me hope it helps until we get some cooler mods. Also, i would like to see toolbox app intergrated into the mega 6.3, im able to bring up options in xsposed module but nothing happens.

I deleted the other two pics but they won't go away yet 😕