Slackmojis - A directory of the best custom slack emojis
PlayPlay.io - Chess and Ping Pong tracking in Slack
Discord Emoji - Iconfinder, but for emoji.
Pinpon - The ping pong bot for Slack
Emoji Builder - Create your own emoji in no time 💨
Ranked.Fun - An online leaderboard with your friends for your favorite games (Ping Pong, Foosball, Smash Ultimate, Chess, etc.)