Photostash - Automatically save your pictures from Slack to Gdrive
EventsBase - Find the best professional events nearby or globally
Heymarket for Slack - Text and Facebook messaging from Slack
Rally by Eventbrite - Find the best local events and rally your friends to join
Slack It - A bookmarklet to share links in Slack with one click
Calendall - Follow the best events online, without leaving your couch.