1. To enable or disable Dual window, from the home screen, swipe down from the Notification bar.
   
2. Tap the Settings icon.
   
3. Under the 'General' tab, scroll to then tap the Dual window switch to toggle on/off.
   
4. To use Dual window, from any screen, press and hold the Back key.
   Note: Alternatively, press the Recent apps key, then tap 'Dual window'.
   
5. Tap the app you wish to display in the upper half on the screen.
   
6. Tap the app you wish to display in the lower half of the screen.
   
7. A Blue border surrounds the active window.
   
8. To resize the windows, drag the Dual window tab up or down.
   
9. Tap the Dual window tab to access options.
   
10. Tap the Swap icon to switch the apps displayed in the upper and lower windows.
    
11. Tap the Apps icon to access the list of Dual window apps.
    
12. Tap the Maximize icon to open the active window in fullscreen mode.
    
13. Tap the X icon to close the active window.