Easy split screen : Multi Wind
easy-split-screen---multi-window
About App
If you want to work with two different apps at the same time then you can do it using the Easy split screen : Multi Window. This app creates dual windows on your phone screen so you can do multitasking.
To split your screen into two parts first you have to enable split-screen service from the app. Then there are two shortcut ways available to get the split-screen, the first way is using the floating button and the second way is using the notification.
Developer info