Samsung Galaxy S7 / S7 edge - View, Open or Close Recently Used Apps
To view the most recently used apps, tap the Recent apps icon (located on the bottom left) and scroll through the list of apps.
To display the icon, tap the lower-left corner of the device next to the Home button.
To Open or Close:
Open: Scroll to and tap the desired app(s) in the list.
Close: Scroll through the list of apps, hold the app then swipe the screen left or right.