How to close apps from Mission Control on macOS Sierra?
I have recently bought a new MacBook Pro after 4 years of using Windows, and I really missed the ability of directly closing windows in Mission Control, as I used to do in my good old Mac OS X Snow Leopard.

I have searched around the web and in macOS Sierra settings, but I didn't found a OS native way of achieving it.

So I installed this little tool (I also used it in the old days) called Better Touch Tool. It allows you to set customised keyboard and gesture shortcuts.

I use a 3 finger tap to close windows directly bellow the cursor (which works anywhere, even in Mission Control). You can set up any shortcut you want. I find using it very convenient, I hope you do also.