Plug-in to make first post permanent?

I need to make the first post on my blog permanent, like a static page, but also showing the latest 5-10 posts below it.

I found a plug-in that seemed to do this, but was called away to attend to an emergency (injured 2 yo grandson), and now I can’t find it (I found it by accident the previous time).

Does anyone know the plug-in that I’m looking for please?

John