It happens to the best: you add new features to an app localized in several languages. You are not the lazy type that names the NSLocalizedString key’s the same as the English-language strings. Instead you name the keys semantically, like DOWNLOAD_ALERT_MSG.
Then when it comes to shipping you send the client a note that there are some new strings and assume that he will be able to find out which are new and need to be translated. Which he would if he was using a tool like Linguan. Which he is not, because you might have forgotten to recommend it to him, or if he’s extremely unlucky then he’s a Windows user.
