We've released a feature under the Audience tab in the analytics for your iOS applications called Language Metrics. This new view shows you a breakdown of the preferred language of your users.
Figure 1. New Language Metrics View
These new metrics can be invaluable in planning your internationalization strategy. Translating your application into other languages (internationalization) can be an expensive undertaking so prioritizing the most popular languages is important. Language Metrics provide you a simple way to identify the most popular languages and regions so you can make sure to translate into those languages first.
Where does the data come from? Smartphones allow users to specify their preferred language (also known as their locale) when they set up their device and applications that support internationalization can use it to customize their interface for these users. For example, an application that supports internationalization might appear in English to a user in the United States but in French to a user in France. Even if your application doesn't support the preferred language of the user this preference information is still provided by the phone and collected by the Flurry SDK.
To browse your Language Metrics simply select one of your iOS applications and navigate to the Audience tab and click on Language. You will see a summary view of the top languages preferred by your users, with the option to view popularity by a number of metrics (New Users, Sessions, Active Users, etc.). You can also drill down into a language to view the most popular countries for that language which can be helpful since many languages have regional dialects.
We are working to add this same feature to other platforms in the near future.