That untethered jailbreak arrived in the form of evasi0n, a jailbreaking tool for iOS 6 up to iOS 6.1.2. (If you've updated to iOS 6.1.3 or later, you won't be able to use this method to jailbreak your iPhone - and if you update after this process you will lose your jailbreak. See below for alternatives.) Like jailbreaks before it, evasi0n doesn't unlock an iPhone (which would allow you to use the device with multiple carriers). Rather, it simply allows you to install third-party apps not approved by Apple via the Cydia store we mentioned earlier.
How to jailbreak an iPhone: Breaking it down
To begin the jailbreaking process, back up your device. You do this by plugging it into your computer, launching iTunes, and choosing File > Devices > Back Up. This helps ensure that any data you have on your device can be later restored.
Before jailbreaking, be sure to back up your data
Now download a copy of evasi0n from one of the mirror sites listed on the evasi0n site (it's a download of just over 10MB). Double-click the .dmg file to decompress it and an evasi0n window will appear on your desktop. Drag the evasi0n application out of the window to the desktop and launch it.
Connect your iOS device and click the Jailbreak button. evasi0n will retrieve some information from your device. The device will then reboot and prepare itself for the jailbreak. Don't do anything with your device during this stage.
evasi0n will now install Cydia - the application that provides access to third-party apps - on your device. When instructed to by evasi0n, unlock your device by pressing the Home button and swiping the Slide to Unlock switch to the right. You should see a new Jailbreak icon on your Home screen. Tap it and evasi0n will carry on with the final stage of the jailbreak. You can now quit evasi0n by clicking the Exit button.
Your device will reboot, briefly display the evasi0n screen, show the Apple logo, and then show the evasi0n screen again, which details the progress of the jailbreak installation. Finally, your device is ready for you to use in the normal way.
The one difference you'll see is a Cydia icon on the home screen. Tap it and Cydia launches, prepares its file system, and then quits. To then use Cydia as intended, tap its icon once again, choose your user type (User, Hacker, or Developer), tap Done, and the Cydia interface loads.
The version of Cydia you're using may need updating; older versions of Cydia may not support Cydia's newer third-party apps. To do that, tap the Changes icon at the bottom of the screen and then tap Refresh in the top left corner. If any updates are available (as evidenced by green check marks) tap the Update button in the top-right corner of the display. Cydia will download the latest updates and reboot the device.
Sign up for Computerworld eNewsletters.