Although iCondubber is less user-friendly and fully-featured than alternative CandyBar, it holds its own as an icon management application and it is still under active development. iCondubber’s interface makes it clear that you are diving into system files to change the appearance of things, which should remind you to back off if you don’t know what you’re doing. If you do know what you’re doing, it’s potentially a more powerful application than CandyBar.
The iContainers favored by CandyBar are also supported by iCondubber.
Note that, for some reason, you may have to download an older version of the software if you have a newer version of OS X. Mountain Lion is officially supported by the most recent release; click the secondary download link for a version that works on Snow Leopard and Lion.