Touch and hold the Back Key (in the Touch Keys bar) to split the screen.
Tap the app icon you want to use. The first app you tap opens in a window at the top of the screen. The second app opens in the bottom window.
Tap a window to select and use it.
A blue box appears around the selected window with a blue semicircle handle between the windows.
Drag the blue handle to change the window sizes (one larger and one smaller).
Tap the blue handle to access the Dual window options.
Tap the Swap icon to switch (flip) the app positions.
Tap the View app list icon to redisplay the apps list so you can change the app for the selected window.
Tap the Open full screen icon to open the selected app in full screen. Drag the blue handle (up or down depending on the selected window) to return to Dual window.
Tap the Close icon to close the selected window.