Cydia is a graphical user interface of APT(Advanced Package Manager) for iOS. It enables a user to find and install software not authorized by Apple on jailbroken iPhones, iPads and iPod touch devices. It also refers to digital distribution platform for software on iOS accessed through Cydia software.[2] Most of the software packages available through Cydia are free of charge, although some require purchasing.
Cydia is developed by Jay Freeman (named "saurik") and his company, SaurikIT. The name "Cydia" is a reference to the moth genus Cydia, notably the Codling Moth (Cydia pomonella).[3]
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. Cydia is based on APT, ported to iOS as part of Jay Freeman's Telesphoreo project.[4]
Packages are downloaded through a list of repositories. Packages are installed through the list of repositories a user has installed. Apps are installed in the same location as Apple's own applications, in the /Applications directory. Jailbroken devices can also still buy and download apps normally from the official App Store.[5] Some jailbreaking tools install Cydia automatically, while others may not.
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.[6][7] Some Cydia repositories host open source packages as well as paid modifications for jailbroken devices. These modifications are based on a framework called Cydia Substrate (formally MobileSubstrate).[3]
Many Unix/Linux command line tools are available on Cydia as well, including bash, coreutils and OpenSSH, meaning the device could potentially be used as a full-fledged Unix workstation, although missing some development tools.