Dr. Drang, on the history of multitasking on Apple products:
When the iPad came out, it was deja vu all over again. One screen, one app. Before the end of 2010, iOS 4 provided the Switcher-like multitasking bar and the ability to quickly shift from one app to another. Still only one app on the screen at a time, though. And while the multitasking bar has grown from a strip of icons into a set of screenshots, it’s still more like the Switcher than the MultiFinder.
Until iOS 9.