It is rumored that there are over 10 million jailbroken Apple iOS iDevices (iPhone, iPad and iPod Touch) in existence today and for the more dedicated hacker jailbreaking your iOS device is essential.
Benefits of jailbreaking your device include greater customization options and the ability to install apps which have been rejected from Apple’s App Store including:
- My3G: Makes apps believe that they’re on Wi-Fi rather than 3G,enabling 3G-prohibited features, such as HD YouTube over 3G.
- PDANet: Tethering app that will bypass the AT&T restrictions and allow you to share your internet connection.
- MxTube: Allows you to download and save YouTube videos for offline viewing.
You can read about other apps available for jail broken devices here: http://www.gadgetsdna.com/10-ultimate-cydia-apps-for-jailbroken-iphone-4/5314/
There are three main jailbreaking tools (that working with iOS 4.2.1)at the moment: greenpois0n, redsn0w and limera1n. And all three use the same vulnerability in the device’s boot rom to crack it open. But there are some caveats:
- Jailbreaking on the iPhone 4, later iPhone 3GS models, third generation iPod touch devices and the iPad, use what is know as tethered jailbreaking meaning that you will have to boot your device into the jailbroken state every time you reboot. What this means practically is that when you reboot the device you need to have it physically connected (tethered) to your Mac or PC with the jailbreak software running. If you reboot the device while it isn’t tethered it will boot back up without the jailbreak in place.
- If you are trying to unlock your phone (using a tool like ultrasn0w) so that you can use any mobile phone network you need to be aware that ultrasn0w doesn’t yet work on iOS 4.2.1.
It is expected that both of the above problems will be solved in time, but there are no guarantees as to when.
For those who want to try this out, here is a video tutorial on jailbreaking an iPhone running iOS 4.2.1 with Redsn0w: http://www.youtube.com/watch?v=P6RJcxqFdE4&feature=player_embedded