I’d like to suggest adding Russian language support to your product. There are roughly 250–260 million Russian‑speaking people worldwide, of whom only about 115–155 million are native speakers (mostly in Russia itself). That means well over 100 million people who speak Russian are not ethnic Russians, including large communities in former Soviet republics such as Ukraine, Belarus, Kazakhstan, Armenia, Georgia, Azerbaijan, Moldova, the Baltics, and others.

Adding Russian would significantly expand your potential user base across multiple countries.