Kontakt
3.0 out of 5 stars (based on 1 review)
Sieť Kontalk je komunitou riadená sieť okamžitých správ určená pre smartfóny a tablety.
You have to provide your phone number in order to use kontalk. Apart from that, kontalk seems to be quite trade-free, because there are no ads or trackers. Everything is end-to-end encrypted by default.