Eclipse is almost certainly the most instantly noticeable tweak so far, however — taking the bright colors that are standard with the iOS UI and replacing them with a darker palette of colors and shades to give your iPhone a suitably moody “night mode”.
The tweak is the work of developer Guillermo Morán, who has been providing updates via his twitter account @fr0st. While Eclipse is currently available only for iPhones, an iPad tweak will hopefully follow shortly.
There are a few bugs, particularly with certain fonts appearing gray against light gray backgrounds, but for the most part this is a great tweak for opening up the darker side of iOS — and Morán is improving it all the time.
Eclipse costs 99 cents from the Cydia Store.