Since this came up again -- we recently did an analysis on a data-set of over 100 million of the app store reviews across different countries. English and other european languages were extremely prevalent, with english dominating. The people who tend to use fancy smartphones etc are much more likely to speak english and are also exposed to english language content, apps, etc. For example, in Israel, 51% of reviews are in english while only 46% are in Hebrew. More examples: http://blog.sensortower.com/blog/2013/11/27/what-apple-app-s...