Tricks I Accidentally Found

When I open an app then, going to home screen, something strange happened. I was putting a widget then something pop up. It was the app from the recent tabs. I think this is a new feature in one ui 4.1 but its annoying how i cannot do this all the time and how to work this thing properly. I hold my finger in the middle of the screen and in order to run the pop up screen it needs one app running in recent tabs (*idk what is call?) Is this new or old, let me know.