Update (3/10/13): FoncÚ now fully supports iOS 6.1 and the iPhone 5!
FoncÚ (french for dark, darkened) is an interface overhaul of Notification Center, meant to replace Apple's blueish, linen-styled and in my opinion not very attractive design with a dark, smooth and matte user interface which accentuates the displayed information (black-white goes way better on the eyes than blue-white does), while looking a whole lot more polished at the same time.
The theme comes in both Retina and non-Retina resolution and is usually installed in two easy steps. First, place either FoncÚ HD.theme or FoncÚ SD.theme in your themes folder and activate it through WinterBoard. This takes care of all widget-independent UI elements and the background images for some of the most popular widgets.
This might be all you need to do already, but depending on the widgets you use, some of them might not be properly themed yet. To change that, navigate to /System/Library/WeeAppPlugins/ and open a widget folder you'd like to theme. Now you have two possibilities:
Either drop me a short message containing the name of the widget, and I'll update the theme with a background for it. As this won't only solve the problem for you, but also for other people, I'd be happy to hear from you!
Alternatively, if you don't want to wait for a theme update, open up your resolution's Widget Background folder from the downloaded package and replace the widget's WeeAppBackground.png or WeeAppBackground@2x.png with the image inside. For very small-sized widgets, the background gradient might appear cut off; in that case, choose the version inside the For cut-off Gradients folder instead.
Please let me know if you come across any problems, particularly with the non-Retina version, as I was not able to test it. Apart from that, enjoy!
So, yesterday I was challenged by the one and only Jonathan Mazaltov (aka Mr. Awesome aka 1 half the genius behind the incredible Siri tweak "Lingual" (in Cydia now) AND Codethemed.com) to make a Snowcover theme that could be used with ANY wallpaper the user liked.
So like any good Barney Stinson fan I yell at my computer screen, "Challenge Accepted!" and got to working on it this morning. This one took some thinking, some trial & error and a few tears, BUT I think I may have it or maybe the beginnings to inspire someone else to do way better after seeing my crap ha.
To install a Snowcover theme, just SSH into you iDevice and place the theme "/Library/SC4Themes" and select the theme in settings.