Cydia, created by Jay Freeman (saurik), was the first major alternative to the App Store, using a Debian-based package management system (APT). While Cydia required a full system exploit (jailbreak), modern users often prefer sideloading individual which do not always require a fully compromised kernel.
: A popular tool for sideloading .ipa files onto both jailbroken and non-jailbroken devices.
: Cydia technically supports devices from iPhone OS 2.0 through iOS 12.4, though modern jailbreaks (like Palera1n or Dopamine) often use newer managers like Sileo or Zebra . Popular GitHub IPA Archives