iPhone starting on app from another, shows tab at top of screen

On iPhone running ios9 first beta, if I start one app from within another app I get a 'tab' at the top left of the screen on the second app. This tab has the display name for the app the current app was started from, and tapping this tab opens that other initial app. It is a way of switching between apps. Is there some documentation for this behaviour? Can it be turned off?

iPhone starting on app from another, shows tab at top of screen
 
 
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