It's obvious that to gain more customers on any given platform, one of the most important steps to take would be to localize your software into many languages: as many as possible, ideally. However, with independently developed apps, it tends to be difficult to localize into many different languages, due to not having the budget and / or time to do so. My question is if I were to localize my apps into languages other than English on the iOS App Store, which languages should I prioritize? (Maybe the top three or four most important.)

_{(Also, let's pretend this is a generic app that won't cater more to one language demographic than another.)}