In my experience living in Spain and Japan, depending on the app type many users will put up with only English version to try the apps out or because they are c

In my experience living in Spain and Japan, depending on the app type many users will put up with only English version to try the apps out or because they are cool; they are not the majority, but many young educated users will do. Also note, Spain and Japan are infamous for low English skills. In this area, I'd say that apps with little interface text/intuitive icons (such as camera-type or even chat apps) and apps for learning new languages (these users are likely to know English already) can get away with it.