At the moment I'm using two displays for my MacBook. The larger screen is the one I primarily use because of its available space. The smaller one (MacBook) is used to glance on if I ever need to check something. In the case that I watch a class on the secondary while working on the primary and something important comes up, I would like to switch the applications displayed on both screens with one keystroke (so if I have TextEdit and Safari open on the big screen, and YouTube on the small, I want to move TextEdit/Safari to the small and YouTube to the big screen with a single keystroke).
Hopefully someone has an idea to accomplish this.