I can't seem to find it in 4.4.1

So I just went to extensions and downloaded these Grease Pencil Tools

but I don't get all those extra brushes so i'm guessing this is something different.

Things have changed dramatically since 4.3, and brushes are this biggest. If you would like to find those brushes, Daniel Lari posts a video of where you can get them: https://www.pepe-school-land.com/grease-pencil-brush-pack
Here is his short how-to video on how to install: https://www.instagram.com/p/DH8SN4rNyL1/?hl=en
I'll try and post some updated stuff next week, but personally, I don't like how Brushes are currently either assets you cannot edit (like this file) or they have to be manually dropped in a folder and pointed to through Preferences>>File Paths>>Asset Libraries. I've created a small pack for you here: https://cgcookie.com/downloads/paul-s-grease-pencil-3-0-brush-pack
And if you follow this video: https://www.youtube.com/watch?v=FHu6X_N3qjU you should be able to manage and create your own custom brushes in the new system