third party [thurd-par-tee]
1. Video games. Describing hardware or software developed independently from the primary developer on a platform.
EX. This week's first Unbox-King video is about some third party accessories, and a first party controller, that I picked up on Amazon to improve my Smash Bros. experience.
Because everybody should be able to enjoy playing Smash Bros. with a wired Gamecube controller, as Miyamoto-san and Sakurai-san intended.