iOS (jailbreak): Winterboard, the popular iOS skinning tool, has been updated for iOS 7. It's also now compatible with newer 64-bit devices like the iPhone 5s, the iPad Air and the iPad Mini.
Winterboard has long been the best way to customise your iOS device using themes and skins, so it's nice the update brings those features to the new OS. Not much is really new other than the devices it supports, but what really matters is that it works.
Users of newer 64-bit devices like the iPhone 5s and iPad Air might need to hold on a bit for themes to get updated for the new version, but everyone else can get to customising right away.