QuizUp - QuizUp gives you the opportunity to test your trivia skills against friends and strangers throughout the world.
Trivia for Google Chat - Team-building w/ fun quizzes, games right inside Google Chat
A Google a Day - Online trivia game where you use Google's search to answer questions as fast as you can.
Social Games in Slack - Polly brings your WFH team together with interactive games
Trivia Crack Kingdoms - The amazing quiz game that lets you test your knowledge and challenge your friends to see who is the smartest. Developed by Etermax
Flinkit! - Web-hosted team building games for small and large companies