[saagarjha]

> it took me awhile to get the hang of pressing down on one of the little cards representing an app in order to evoke a minus sign that allowed me to close it.

You're not supposed to perform this action regularly.

> I knew I’d mastered the gestures when I found myself trying to use them on my iPad. Oops. My finger no longer drifts to the home button, but pathetically swipes upwards, to no avail.

This should work on iPad if you're running iOS 11.