The BigBoss Repository is a default installation on all jailbroken devices with Cydia. It offers a wide range of categories including add-ons, carrier bundles, data storage, education, entertainment, fonts, games, keyboard, messaging, multimedia, navigation, productivity, ringtones, security, terminal support, themes, utilities, widgets, and more. It is compatible with iOS 4 up to the latest iOS 15 and provides access to thousands of add-ons, including Siri, DreamBoard, ControlCenter, Spotlight, and more.
You can add the BigBoss Repository URL to your Cydia Sources to access new applications and tweaks. It is worth noting that the BigBoss repo is also installed by default when using popular jailbreak tools like unc0ver or checkra1n.