VixT on Slack - The best video mashup app now on Slack.
GitHub Visualizer - Enter user/repo and see the project visually
Slack Meme Bot - Spice up your team conversations with memes
Refined GitHub - Browser extension that makes GitHub cleaner & more powerful
GoGifApp - Free Slack GIFs App, multiple images to pick from at once
Commit Together by Github - Now add co-authors to your commits