Slide over functionality?

Is it possible to use the side of your mac menu as a slider over the trigger? Kind of like hot corners but I want to show/hide a certain app.

I could have sworn there was an old mac app I used to do this but can't find it anymore.

Rather than replicating what you used to do, how about using a gesture to trigger the action you want? See This could be more fun than just sliding to the edge of screen.