The iPhone offers a huge variety of applications(commonly known as iPhone Apps,Apple Apps,or just Apps)that can only be gained through the official online Apple store(also known as App Store).These applications come in diverse genres,such as games,GPS navigation systems,social-networking,multimedia,and others.Currently there are over 20.000 apps available on the App Store.At such huge number,most apps can be useful,but some can be less useful,or just considered unnecessary due to the popularity that the domains they represent lack.
There are currently four generations of the Apple iPhone available(the iPhone,the iPhone 3G,the iPhone 3GS and the iPhone 4)and each of them brought something new to the table,such as 3G video calling,in the case of the iPhone 3G,certain features were kept through are four generations,like the screen size,or the button alignment and positioning.In order to use the internet and multimedia features of any of the four iPhone types,you must first activate it as a mobile phone with a proper carrier.However,on July 3,2007,Jon Lech Johnson succeeded in bypassing this requirement with the help of some software and editing of the iTunes binary,which has later posted on his personal blog alongside indications of how to use them so everybody can trick Apple in unlocking the iPhone.
The iPhone 3GS however was harder to crack,as it required an in-store activation of the phone.Even tough it was harder than with the original iPhone,the iPhone 3GS was also hacked into allowing users to access the multimedia and internet features without the activation as a mobile phone.Both the need for in-store activation of the phone and a huge number of Apple iPhone users that were updating their devices to the OS 2.0 software,cause the Apple servers to overload.
The OS 2.0 software the iPhone 3G were launched in the same day of July 11,2008.Apple launched the 3.0 update to its software just a few days before the launch of the iPhone 3GS(the third installment to the iPhone family) due to the large number of unhappy customers that complained about their phones temporary not working after they were asked for activation when they updated the software to 2.0
Most iPhones are sold with a SIM Lock that restricts access to the device to one particular carrier that you have to register.This practice is commonly met at the subsidized GSM phones.Opposing the GSM phones however,the iPhone cannot be activated by introducing a serial number or code.
The iPhone was original registered in the U.S to AT&T,but hackers developed a method which they used to register the phones from other networks,as statistics show that over a quarter of the sold iPhones were not registered to AT&T.AT&T started to sell phones without contract at a double price because Apple and AT&T lose the differed income this way.Policies in other states differ however,and you do not have to register to AT&T if you are located somewhere over the sea.