Windows 8 screen-style Snap View multitasking feature could place two apps next to each other in split only 70/30 windows. However, one app takes up the most screen and that make the other unusable. Now Windows 8.1 improves multitasking for spliting multitasking apps’ screens in ratios of 70/30, 60/40 or 50/50.
How to Use Split Screen Mode in Windows 8.1 apps on Surface Pro and RT
Method for enabling multitasking with two Modern UI apps
* First open the two Modern apps, and run one of them into full screen.
* Simply swipe in from the left and then hold your finger.
* When the second app dock shows up on the left side, release your finger.
* Now the screen is taken up 50 percent by each app.
* To view smaller or larger or for any of them, tap and hold the black vertical line and drag it to the right or left.
If you would like to enable Multitasking within Internet Explorer 11 app, try this way:
* Run the IE 11 Modern UI app into full screen and open a web page.
* Simply right-click a weblink, and select “Open in New Window”.
* Now each of two Internet Explorer windows takes up half of screen and you could try the above method to split screen.