You’re discounting the fact that there’s plenty of internal movement in Europe - I worked with a French firm that had a bunch of Italians, some Swiss, an Englishman, two Spaniards and a bunch of Russians working there along with the French people, all living around and working in their Paris office.
It wouldn’t be that hard to find people to translate your app and provide support in the major languages in most large European cities.
In the US, you don't have to find people to translate your app and provide support in other languages at all. It would help if you did this for Spanish though, but that's it.
It wouldn’t be that hard to find people to translate your app and provide support in the major languages in most large European cities.