I recently discovered the show/hide action after using triggers to open/launch apps for a while. I then just discovered that show/hide works even better with apps in fullscreen mode as you can switch to and away from the app with the same trigger. I use this now for messaging and audio player apps that I leave running in fullscreen. Pretty damn impressive!
A followup tip about this: When using this for fullscreen apps it only seems to work well for dedicated fullscreen use and not when you're splitting a space between two apps.
In the split-view case it will take you to the split view for the triggered app but will not hide it again. You have to have the app running fully in its dedicated space.