Themed Apps:

Team Blacked Out - Discussion thread on their inverted and transparent app collection. Check the OP for a link to their website and the Free Updater App. An app for your phone to browse and download their stuff!

Air Command theme for Kit Kat 4.4.2 n900/9005/odexed/deodexed - 100+ Air Command Themes!
Found by @jrbxx7

Transparent Widget Skins - Thread where users can request a "widget" to be made transparent! Use what they got already, or request one you would like to see!

Black and Blue themed Tapatalk
Black and blue and beautiful. By @cerj. See post #1038 in his thread.

Other theming resources:

KAT Kit - A very cool 7Zip add-on to assist in theming/batch theming plus a whole lot more!! @Kdio is doing some great things over here, and you should really check this out!
I will not apologize for art.