It boggles my mind that I have to remind many app publishers that we live in a globalized world and that it’s a natter of a few minutes work to just select the countries to make the app available in. More so for free apps where the publisher doesn’t have to worry about taxes and payments.
Even for apps that are not localized to English or other languages, the publishers should prefer to get them out to as many people as possible in the whole wide world who may be visiting or on a long stay in a specific country.
In this case, the app developer can surely include help text that explains where the app is meant to be used or would be useful (it’s also not like people with a German App Store account living in some other country would be able to use this app effectively).