iPod Touch 5
iPod Touch 4
Apple TV 2 (NOT 3rd generation)
The unteathered status means that you can safely reboot your device without having to have it "tethered" to a computer in order for it to remain jailbroken and work. The tool is available for Mac OS X (10.5 or later), Windows XP or newer, and Linux from the Evasi0n Website. One thing that they are suggesting is that you should update to the latest firmware for your device but not using the OTA (Over the Air) method but you should download the firmware thru iTunes and update your device through iTunes. They are also recommending that you should fully back up your data via iCloud or iTunes.
I am very excited about this as I have been waiting for an unteathered Jailbreak since I got my iPhone 4 back in December of 2011 and now I have an iPhone 4S and can't wait to "release" it from the grips of Apple so that I can take full advantage of the hardware and it's capabilities by using apps from the most popular repository for community developed applications, Cydia. Will you be jailbreaking your iOS device?
Here's a tutorial I put together which shows how to update to the latest firmware and then perform the evasi0n jailbreak within Xubuntu 12.04.