[iOS concept] Close Multiple Apps (video)

I know that it's unnecessary to close apps since it doesn't use any resources aside from memory but when you decided to declutter, it's too tedious to do it. Also, because the multitasking tray gets cluttered, doesn't that makes it unappealing to use? doesn't that makes us rely on homescreen even in switching between apps? especially on the iPad where multitasking is lot easier with the 4 finger gesture.. would't be better if there's a faster way to close apps?

Here's my another concept. It's for Facebook though. I posted this in Web & Social but it looks like there's only few visitors there.