So far for every version of an operating system update there has been a Jailbreak. The term “Jailbreak” was initially introduced when people began cracking their operating system software in order to install apps that would otherwise have to be purchased.
With the new release of the new iPhone 5 Apple took the opportunity to introduce to the world their brand new operating system the iOS 6. Obviously the iOS 6 comes preloaded with all new Apps and upgrades however for anyone who is planning to upgrade to the new iOS using their older version devices such as the iPod touch 4th generation or the iPhone 4 that would ultimately mean the preinstalled jailbreak on that particular device will be void and useless. That is why people are often advised not to upgrade their software because it could cause problems for a Jailbroken device. And although latest news reports suggest that a developer hack has been released for A4 devices willing to upgrade to the iOS 6. Here is a full list of tweaks compatible by Adam Insull . The Google docs can be checked out for further details.
However this move may not be advised since the developer hack requires people to install Cydia manually and unless someone is fairly skilled in the art of jailbreaking it is certainly a tough task. The jailbreak is also tethered which means it needs to be redone every time the iPhone or the iPod restarts. Since the Hack has been released there are users that have tried and uploaded many tweaks in order to design a perfect theme. These tweaks have been uploaded with a list and can be checked and reviewed.