Hang on, this should be the number 1 point of your entire blog post. Honestly, if your post was titled the obvious "Don't make mobile apps only for one region" then you'd be getting a lot of comments saying "Well, obviously".
Seriously your problem here is not that you made a mobile app. Your problem is very clearly that you excluded 99% of your user base. Any chance you can explain the reasoning behind this..? I can't even begin to understand it. Outside of government required tax applications, I cannot think of a single successful single-region productivity app ever.