Add-ons are a way to extend Playnite's functionality. Add-ons can provide integration with various game libraries, metadata source and extend other generic features. Playnite look in both Desktop and Fullscreen modes can be also changed using add-ons.
Add-ons can be installed using 'Download' buttons on the list below (if you have Playnite already installed) or in the Add-ons menu inside Playnite.
You can learn more on how to create and publish add-ons in the Docs.