As you probably know Skype is translated to no less than 27 languages! Since we are such a global company it is important for us that as many people as possible can use Skype in their own language.
If you are building any kind of add-on to Skype I strongly suggest that localization is important for you also!

Of our users 72% don't have English as the selected language in Skype. So if your app is only in English - 72% of your potential users are not seeing it in the language they would prefer!

To make this a bit simpler for you, we have published a list of more than 2600 phrases used in Skype translated to all of the 27 languages. It's a rather impressive list, imho:

To download - simply go to this URL: https://developer.skype.com/Download/SkypeStrings

The strings are in a Unicode text file that you can use on all platforms. We hope you will find it useful and that it will get you started towards doing a full localization of your products.
Good luck!