Note: iLocalize has been discontinued, but the 4.3.2 beta version can be used for free.
iLocalize is a powerful and intuitive application designed to help developers localize their applications. iLocalize handles multiple languages in the same project, offers custom glossaries, and has powerful features to help incremental localization.
Simply stated: save a lot of time when localizing your application with iLocalize. Note: The app is listed as free, but it is actually donationware; consider making a donation to help stimulate development.