...
In iOS 9 and later for supported devices such as iPad Air 2, iPad Pro, and later Logbook Pro supports Split-View and Slide-Over. Drag from the right side of the screen to initiate slide-over. On the left vertical edge of the slide-over window is a small white vertical bar. Drag this to initiate Split-View allowing two apps to be viewed side-by-side. On newer versions of iOS, tapping on the 3 dots at the top of your screen initiates these split screen modes.