Cydia is a APT-based package installer and manager for the iOS. It is currently the best way to get access to all the applications, utilities and other wonders of jailbreaking.
You most likely already have Cydia if you jailbroke with a normal jailbreaking app. This is here in case of Cydia getting corrupted or any other problems, so you can install the deb with dpkg.
You most likely already have Cydia if you jailbroke with a normal jailbreaking app. This is here in case of Cydia getting corrupted or any other problems, so you can install the deb with dpkg.