Use it as a fun experiment to see how much you can grow it not how much you can monetize. Formulate some assumptions and test them. I'd personally pick one of the countries and see if I can push installs in that country hard (might be difficult due to language issues). Try to figure out how people learn about your app and install it. Figure out what phones it is installed on and write a blogpost on using your app on that phone etc.
55k active users isn't bad. If you keep on growing someone will get interested even if you didn't monetize before (possibly even because you didn't) especially since it's not a "fad app" but something sustainable as long as there's low resource phones. [worst case you can use it if you ever want to apply at Facebook]
tl;dr: use it as your private growth-lab and learn a lot :)