What version of PS are you using? Does that addon support that version of PS?
It would be under Window > Extensions as "Adobe Paper Texture Pro". The textures are courtesy of Flypaper, but that's not the name you would find it under.
I also see the Texture packs for sale, but they are 4000 x 4000 pixel jpegs which would be like stock art you add to a project.
You can use Adobe Paper Texture Pro to load and manage your Flypaper Texture folders that your purchase, and than select the texture thumbnail for the texture you want in your project but the Texture manager is a CC exclusive. so if you have CS6 or under, you would have to import texture you want.
I have version 3.1.2 running OK in CC 2017. Installing Extensions can be problematic since CC2014, but so long as you have the HTML5 version, and follow the installation instructions, this particular Extension should fine. It's an excellent tool as well, but probably best not to overdo it.
At our monthly Camera Club meetings, there's one particular person whose competition entries I can always spot due to her relentless use of textures, and as often as not distressed edges. It's an affectation that distracts and hides issues with the underlying image. There's a time and a place for using texture, and come to think of it, I can think of no better example than Chuck Uebele's (who was the first to respond to your question) rather famous image 'Cutting Through the Grunge' The clue is in the title
Most recent 2017.1.1 at least it just updated today.
Well then I don't really understand how this works. I have the Adobe Paper Texture Pro and it shows up in photoshop under the extensions. I also have the Flypaper Taster Textures in a folder on my desktop. I guess I need to add them somehow...how do I do this?
First from the dropdown menu, choose "Select a folder".
Next,the folder dialog opens. I keep all my Flypaper folders under Documents/Textures Library (MacOS)
I choose the folder:
I answer Yes on this dialog: (You may have to drag the File Open box to the side before clicking on Open as it sometimes hides this important dialog.)
Then the default library is replaced by the Flypaper Pastel Painterly, all set to go.