Cydia

Cydia is an app developed by (a.k.a. "saurik") to allow the installation of software on "jailbroken" devices designed by Apple Inc. This makes it possible the download and install software from sources other than the Apple App Store onto devices running operating systems such as iOS and iPadOS, which have protected privileges by default.

History
Freeman developed Cydia from 's for installing software on the first iPhone, which switched user privileges from "root" to "mobile" in the firmware update to iPhone OS 1.1.3 in January 2008.

In December 2018, Freeman officially shut down the Cydia store payments system due to the discovery of a serious bug, though the software itself remained functional. Though new paid downloads from the repository were no longer supported, Cydia could still be used to install free downloads or use 3rd-party payment systems (such as PayPal) through other repositories