These are dumped versions of games modified with a "fake" verification. They are designed specifically for jailbroken consoles and do not require official licenses. How to Install Games from YouTube PKG Links
files (for the game or YouTube app) are placed in the root directory of the drive. Installation: On the PS4, users navigate to Debug Settings > Package Installer
You might wonder why someone would "download" a YouTube PKG when the app is free on the Official PlayStation Store . The answer lies in No-PSN versions Jailbreak Safety:
