cyCircled is a small Ace2-based addon that changes the look of various buttons (mostly action bar buttons). Currently those addons are supported (or have partial support, as not every part is skinnable):
Bongos (main-, pet- and classbar)
cyCircled is based on plugins, so addon support is easily to be added as long as the IDs of the buttons follow the common naming scheme (icon texture, cooldown model etc.).
At the moment it's possible to change the default color, mouse-over color, "equipped item" color and toggle the various elements of each addon individually on or off (eg. apply the skin to bar1-2 and leave the rest alone). Also, localizations for deDE, koKR and zhCN are included.
The addon is not finished yet and there are still some tweaks/additions which need to be done or are planned to be done.
Any suggestions, bug reports or additional plugins are very welcome