The phone also recognize a huge number of application commonly known as Apps in the iPhone world,that fit in several domains,from games and other interactive or entertaining applications,to social-networking and GPS system maps or add-ons.There are some familiar names in there as well,such as YouTube,Twitter,and many others.
The phone currently comes in four different models,the first one being launched in 2007 and the last in 2010.Every model as its distinct features and improvements,but they all share a set of characteristics that have remained since the original iPhone and are iconic for the device,like the screen size,the button positioning and number,the Apple logo on the back,etc.The iPhone 3G for example,holds the above specified characteristics,but also present something never seen at an iPhone until itself,the ability to make 3G video calls(from where it was named iPhone 3G).
Since the original model,every iPhone required the user to register it as a mobile phone in order to be granted access to the internet and multimedia features as well.This practice is well known as it is frequently used at subsidized GSM phones.Opposing the GSMs however,the iPhone cannot be unlocked by entering a certain code or password.This measure hold for a short amount of time is a man named Jon Lech Johnson succeeded in bypassing this requirement with the help of some software programs.He also edited some data in the iTunes binary in order for he's unlocking to work.He later posted the software and binary edit on his personal blog so anybody could unlock their iPhone.
Then came the second installment of the iPhone family,named iPhone 3G due to its 3G video call capability.This model came with SIM Lock that restricted access to the device to a particular carrier that the user would register when buying the device,as an in-store activation was also needed.
This gave hackers from everywhere a big headache,but in the end,they succeeded in registering the phones from different networks,after(as Apple speculates)they loaded the devices and transported them over the sea for unlocking.Original designated iPhone network AT&T statistics show only a quarter of the total sold number of iPhones were actually registered to their network.They even begun selling iPhone without a contract at a double price(due to the differed income that both of them and Apple would be losing).