Duolingo - Duolingo is a free language learning app for iOS, Windows and Android devices. The app makes learning a new language fun by breaking learning into small lessons where you can earn points and move up through the levels. Read more about Duolingo.

PlayPlay.io - Chess and Ping Pong tracking in Slack

Lingvo TV - Learn languages while watching movies on Netflix.

Pinpon - The ping pong bot for Slack

Fluent - Fluent is a people-based marketing platform that uses real-time, one-to-one interaction to create custom audiences and serve personalized ads that drive performance at scale.

Ranked.Fun - An online leaderboard with your friends for your favorite games (Ping Pong, Foosball, Smash Ultimate, Chess, etc.)