The iPhone has a large variety of applications,which can only be obtained through the official online Apple store.These applications(also known as Apps) come in large varieties,from GSP navigation systems,to social interaction or games.Although there are four generations of iPhone(the iPhone,the iPhone 3G,the iPhone3GS and the iPhone 4) and every model was released alongside a major iOS release and other important updates and upgrades,there are some elements that survived through all versions,such as the button placement the screen size.
The iPhone does not allow access to multimedia players or internet services unless the device has been first activated as a mobile phone with a proper carrier.Jon Lech Johnson however,succeeded on July 3,2007 to bypass the requirement and unlock the iPhone's other functions,as he stated on his online blog.He did so with the help of custom software and changes made to the iTunes binary.He posted the needed software and offsets on his blog as well.This is a bit more tricky on the iPhone 3GS than on the first generation iPhone,because an in-store activation is used.Although it is tricky,it is not impossible for hackers to unlock it as well as the iPhone it replaced.
The need of an in-store activation as well as the huge amount of users that were upgrading to OS 2.0,meant a world wide Apple server overload.Both OS 2.0 and iPhone 3G were released on July 11,2008.The 2.0 however required that users connect to Apple' servers for the authentification of the update,causing a large number of phones to stop working temporary.This was solved with the 3.0 updated that was launched just a few days before the iPhone 3GS (the third installment of the iPhone serie).
Most iPhone models are sold with a SIM lock,which restricts the device to one particular carrier,which is a common practice met at the subsidized GSM phones.However,opposing the GSM phones,iPhones cannot be activated by introducing a password or key serial.The iPhone was initialy sold in the U.S. on AT&T.However,some hackers managed to unlock the phones from other networks,as more than a quarter of the original sold iPhones were not registered to AT&T.Apple speculated that they were shipped oversea and unlocked there.
AT&T started to sell iPhones without contracts,but they cost een double than a contracted device,because AT&T and Apple lose this way the differed income.Policies differ however out side the United States territory.As like with everything else,people found a way to bypass te iPhone's restrictions and use its other functions without being registered ti AT&T.