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.

Cards against Humanity - A party game for horrible people.

Lingvo TV - Learn languages while watching movies on Netflix.

PlayPlay.io - Chess and Ping Pong tracking in 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.

PongUp - The ping pong leaderboard for awesome offices