First of all — I love Spirited Away movie! Don’t you? I guess it’s time to watch it again.
But that’s not what I want to talk about today.
Just recently I found this app that would do things for me for free. Free is awesome so I’ve decided to try it.
It’s called Spirited Away and, as the developer says, it’s purpose is to

check each running application’s activity, and if an application isn’t active for a certain fixed time, Spirited Away hides the application automatically. It is, in effect, Spirited Away

Watch the video below to see it in action and make sure to try it yourself.
And btw, if you’re not convinced yet, but you still don’t know how to hide inactive apps in Mac, your favorite shortcut should be :

Command + H