Trivia for Google Chat - Team-building w/ fun quizzes, games right inside Google Chat
GoodBooks.io - Largest curated collection of 8,500+ book recommendations.
Icebreaker from Range - Start your meeting with 200+ free team-building questions
Read This Twice - Verified book recommendations from people we look up to
meet.atSlack - Team building on Slack
BookAuthority - BookAuthority collects the most recommended books on business, technology and science - as featured on CNN, Inc and Forbes