Many of the most common jailbreak tools used to unlock an iPhone are free. These jailbreak programs, which include PwnageTool for Mac and SnOwBreeze for Windows, can be downloaded directly from their respective websites.
Jailbreak tools allow iPhone users to customize and tailor their device beyond what the iOS Apple operating system allows. iPhones that have been unlocked also have access to Cydia, an app store that is only available after a jailbreak. Cydia has free and pay-for-use app packages that range from games to background and icon themes to functionality extensions.
Unlocking an iPhone with a free jailbreak tool typically requires users to temporarily disable the device passcode, backup the device in case of a crash and switch on airplane mode. iPhones must be connected to a computer in order to complete the jailbreak.