The Samsung Galaxy S4 is a high end phone and it comes split screen feature (Multi Window feature) that Samsung has put in their most expensive cell phones.
Multi Window feature is a unique feature which allows you to easily work on multiple tasks on one screen. For Example: you can take Notes while watching a video or search the web and check SMS messages simultaneously.
Step 1. Go to Settings –> Display –> Multi Window. And just Verify a Green tick mark that appears along with the Multi Window Tray.
Step 2. Pull down your notification panel by dragging your finger downwards from the top of your phones screen.
Step 3.Once you see an icon named Multi window, press it. It should now indicate that it is active by changing color to a light green.
You have now turned on split screen on your galaxy s4. Stay put if you want to know how to use it.
How to use split screen on Galaxy s4
From your home screen press the gray semi circle on the left side of your screen.
Pick the first app you want to run simply by pressing it.
To pick another one locate the one you want from the list. Now press and hold an icon until it detaches from the menu.
Drag it over to the top or bottom half of the screen and drop it.
You can change the size of the windows by pressing and holding the gray line that separates the two apps.
Or if you want you can tapp the gray line to bring up the split screen options. From left to right they are : Switch place, maximize active window and close active window.
Now you can open two apps simultaneously and enjoy both on the same screen.
Using the Multi-window bar is easy enough — to load an app in full-screen move, tap it, To load it in the top or bottom portion of the screen, long-press and drag it into place. With two apps sharing the screen, you can change the way things are divided by dragging the dividing line. Around that line you’ll also see three buttons — one for swapping apps, another to make the current app full-screen, and another to close it. Flip into landscape mode and the apps themselves will rotate, but the dividing line will remain in place.
It might not work with every app, but Multi-window is still one of our favorite TouchWiz features, and if you’re a big multi-tasker — or just someone who wants to watch YouTube and browse the web simultaneously — it could be really useful.