Finn Slack Bot - Finn makes doing things with lists easy and a bit more fun
Coworker Coffee - Coffee with a different coworker each week
BuyerBot Slack Bot - Amazon purchasing for Slack teams
Serendipity - Serendipity is a PHP-powered weblog engine which gives the user an easy way to maintain a blog.
Slackbot Workout - A slackbot to get your team in shape
Twine - Twine is an open-source tool for telling interactive, nonlinear stories.