The Gold Master candidate, for iOS 4 (formerly known as iPhone OS 4), has been out for less than 24 hours, and it has already been jailbroken for iPhone 3G and iPhone 3GS.

Just a couple of weeks ago, when iPhone OS 4 beta 4 was released, we got a new version of redsn0w to jailbreak the iPhone 3G. Well, it turns out, that very same release will work to jailbreak iPhone 3G on iOS 4 GM candidate. Typically, the GM candidate is pretty much the final version of a new OS from Apple, so redsn0w will most likely work with the final release. I have tried this on my iPhone 3G and I can confirm that it works great!

We’ve also heard that there is a 3rd party build of the Pwnage Tool, from msft.guy, that will jailbreak iPhone 3GS on iOS 4 GM. This is not a release from the iPhone Dev Team, so there may be bugs. If you have a “spare” iPhone 3GS lying around, you could try this out, but don’t trust it on your main phone. I have not tried this one.

So, is it worth it to update and jailbreak right now? The main thing you need to think about is, do you need you iPhone unlocked? If you do, STAY AWAY! iOS 4 comes with a baseband update, that it not able to be unlocked yet. The iPhone Dev Team has said they will have unlock and jailbreak tools for iOS 4, after it is officially released, so our suggestion is just wait until we get the go ahead from the pros.

As for jailbreak apps that are working in iOS 4? The only thing really working right now, is OpenSSH. This jailbreak is still only for jailbreak developers to get there apps ready for the official release. Developers may have there apps ready to go, but they have not been uploaded to Cydia yet. This shouldn’t come as a surprise, as we go through this with every major OS update, most recently with the iPad and OS 3.2.