I don't deploy apps on Google Play, anymore (itch.io is my only Android app store!) but on Apple's App Store I try to reply to most reviews. For a long time they had no reply feature, but I like to think that if users see that you reply to reviews they're less likely to say crap. In particular, I like to reward nice reviews with nice responses, and I do contest some negative reviews (recently someone in Canada complained that my dim sum app didn't have enough dishes, and I asked they're over 300, how many is enough? And by the way, I've found that stereotype about Canadians being nice doesn't apply to app reviews) But I try not to be a jerk about it (I've written negative reviews, too, and in one case the author went on a personal attack against me). How you reply is part of your marketing, you want users to support you.
For foreign reviews, I can google translate a "thank you" response or something else short (in fact, before I left Google Play I managed to google translate "visit itch.io" when someone gave me a low rating for having ads and he thanked me and increased my rating). So there have been some cases where they've changed ratings or even when from negative to positive after I responded (one person changed from one-star to five-star after I explained it's just me, not a corporation doing this).
But I also don't worry as much about foreign reviews, as App Store users in the US will only see US reviews (I don't remember how it works on Google Play) and the average of US ratings. I have one app that shows as four stars, but if I go into my developer dashboard I can see the wordwide average is more like two stars.