It’s the Finnish national instrument, but I must admit before my studies I had never heard of it either. 
The Baltic countries have it too: in Estonian it’s called kannel .
The kantele has many variations, as you have seen above. In this song you can hear a kantele in the intro:
https://www.youtube.com/watch?v=ok09aK7cfng
And in Music from Finland - #64 by mirjam_465 you can hear a whole home concert on kantele by someone from the band Nest.
But many countries have some kind of variation on the zither. Iraq for example:
