I localized a part of my application with creating a base.lproj storyboard and 3 string files for it. It was a month ago and after that I added new view controller to app, b
When you click in your storyboard, Main.storyboard for example... On right side you can see the localization menu (see atached image). If you uncheck and check again a lenguage, the file will be generated again. So I usually copy the content, I generate the file again and then I paste the content that I copied and already been translated.
This is the way that I use to update the dictionary.