Hey,
I see that you fixed the names of the cities in Serbia when I click on "Browse by campaign", so, I don't see the question marks anymore (good job!). But, the problem is that only the first 7 characters of a city name are shown. My other suggestion would be that you leave all the names in latin alphabet, because any foreigners that would want to use the app while travelling through Serbia could have troubles with the cyrillic alphabet.
Thanks a lot, you've done a really great job so far! Tamara