Aura is another fantastic jailbreak theme available for iOS devices. It's another icon theme that has a nice blend between flat and skeuomorphism.
The icons use very subtle but eye catching gradients with the glyphs featuring very soft shadows.
Unlike most icons sets that have a slightly rounded corners, Aura features very rounded corners. There are no straight edges as the whole icon is curved.
This is definitely one of the best icon themes available for iOS right now. It's available on Cydia now.
For those wondering, to get the black notification bubbles you have to download the Boover tweak.