Slack Meme Bot - Spice up your team conversations with memes
OctoSearch - Search the repositories starred by your following on GitHub
GoGifApp - Free Slack GIFs App, multiple images to pick from at once
GitHub Visualizer - Enter user/repo and see the project visually
VixT on Slack - The best video mashup app now on Slack.
Gource - Gource is a software version control visualization tool.