Slack News Feed - Get the top posts from every Slack chat you're in.
Slack Platform News - News and updates from the Slack Platform direct to your team
Tettra - Tettra is a company wiki that helps teams manage and share organizational knowledge.
SlackScreen - Full screen public Slack channel display
Slack-News - Read news from multiple sources within Slack by just typing
Google Drive to Slack - Slack notifications whenever you work on Google Drive docs