It would be nice to at least provide a way to try it outside US/CA, like giving a link to an APK here, especially because it's a «Show HN» what means you want to show your product to this community. I wouldn't be too concerned about negative reviews as A) non-hackers will not find this link and will not know how to install it anyway; and B) most people here would be smart enough to understand it's a prototype that is currently limited to one culinar culture, if you explain it while providing the link. This would avoid the frustration that probably more than half of the people are having here when wanting to try your app.
It looks damn cool, but I'm really sad to not being able to try it just because I don't have the right IP address :-(