The Cydia App Store basically acts as an alternative app store for jailbroken iPads, and is packed to the gills with apps and services you won't find on the Apple-endorsed App Store., or
Lots of the offerings on the Cydia App Store are apps that failed the Apple evaluation process, which is known to enforce strict rules. Rather than giving up entirely, developers send their apps Cydia's way, where the jailbreaking community can enjoy them.
The Mac App Store was announced . The idea is that Mac users will be able to install and download apps using the App Store interface. Of course any kind of compatible software can be installed using OS X, but the App Store should make it easier to find and install apps you like. The flip side, of course, is Apple controls which apps make it on to the Mac App Store, and which ones are turned away at the door.
The Mac Cydia equivalent could well attract attention from developers who are rejected from the proper Mac App Store, particularly as Apple won't be allowing things like trials or in-app purchasing in Mac App Store apps.
If it did become popular, Mac Cydia would essentially just be a repository for software you can't find on the App Store -- as OS X isn't strictly regulated by Apple like iOS. Still, it could prove an interesting offering for anybody who owns a Mac.
Speaking at a developers' conference, Freeman (known online as Saurik) said Mac Cydia will launch "within weeks" which means it could well beat Apple's official offering, which is expected before the end of January.
Apparently Cydia has been used by about 10 per cent of all iPhone users -- some 10 million devices.