Excellent tip for iPad users from William Gallagher:
There is something immersive about the way you concentrate on one app at a time with your iPad. Yet so often you need a fact from a website or you need to check an old document. So suddenly you need two or more apps and then it becomes a bit of a chore to switch between them.
That’s exactly what Split View and Slide Over do; even better with drag and drop, though using the fingers instead of a mouse takes some exercise.
Unfortunately, not all iPads can handle Split View and not all of them should. If you’ve got an iPad Mini 4 —but not an older one —it works, but your mileage may vary about the actual utility. The ability to have two apps running on your screen at the same time is superb on a 12.9 inch iPad Pro, for instance. It’s fine on the 10.5 inch iPad Pro.
I don’t expect to see either on future iPhone models.