On-click sliding pop up

Hi
I want to add an on-click pop up to my home page that slides open and shut when the user clicks on it. Can you tell me which plug in would do this for me?
Here is an example of a site where this is used;

https://academic-access.com/

I am using the Responsive theme and my site is:

https://66.147.244.91/~lakesim4//

Thank you!