
Some of the packages available through Cydia are standard applications, while most packages are extensions and modifications for the iOS interface and for apps in the iOS ecosystem. Some jailbreaking tools install Cydia automatically, while others may not. Jailbroken devices can also still buy and download apps normally from the official App Store. Apps are installed in the same location as Apple's own applications, in the /Applications directory. Packages are installed through the list of repositories a user has installed. Packages are downloaded through a list of repositories. Cydia is based on APT, ported to iOS as part of Jay Freeman's Telesphoreo project. Cydia provides a graphical user interface (GUI) to jailbroken users using Advanced Packaging Tool (a package manager) repositories to install software unavailable on the App Store.
