Jay Freeman a.k.a saurik – founder of Cydia and developer of WinterBoard has released an updated version of WinterBoard for iOS 5.
WinterBoard is one of the most popular jailbreak apps that allows you to download custom themes from Cydia, that can be applied to change the look and feel of your iOS device. It is one of the reasons users jailbreak their iPhone.
Please note that though WinterBoard v0.9.3901 is compatible with iOS 5, all the themes available on Cydia may not work with iOS 5. So you might have figure it out by trial and error.
You can checkout the video of WinterBoard running on iOS 5 below:
To find out if your other favorite jailbreak apps and tweaks are compatible with iOS 5, checkout this post for the details.