You can always play Cossacks. It’s a game made in Ukraine, really love playing it on spare time :)

There is also Vinted, which operates across EU.

Asides, in Poland Allegro Lokalne exists, which is making an attempt in the same market.

AFAIK, Sailfish OS has quite strong ties with russia. I love the approach and the choice of technology, and enjoyed it a lot (much more than the iOS/Android approach) — the platform is indeed magnificent and has quite a few great things about it. Although, I see relying on Sailfish OS to be quite a risky choice, given their close ties with russia and unknown status of their support of russian version of the OS.