Samsung's full-screen multi-tasking feature returns on the Galaxy S4. Here's where to find it and how to use.
A favorite feature of the Galaxy Note 2, Samsung's 'Multi-window' multitasking capability is included out of the box on the Galaxy S4. It's probably one of the coolest software tricks Samsung has come up with to date, but it's easily overlooked if you don't know it's there.
To use Multi-window, you'll first need to enable it in the quick settings area. Drag the notification bar down, hit the block icon in the top right corner and make sure "Multi-window" is lit up. From there, you can toggle the Multi-window bar on or off by long-pressing the back key. It's possible to move the bar around by long-pressing the rounded tab while it's open. (To move the tab up or down, simply long-press and drag up or down when the bar doesn't have focus.)