What is this plugin?

This is part of the template, not a plugin ??

This is not part of the theme, or at least the one you can download. Clearly, as the designers, they have customised their own version. I think there are lots of jQuery and other solutions to this that you could implement, but you will need to search around. I’m not aware of a specific WordPress plug-in.

My apologies, had looked at so many things for this theme I got mixed up… I used this as a basis for integrating rollover captions… could maybe adapt for the slide in top info;

https://buildinternet.com/2009/03/sliding-boxes-and-captions-with-jquery/