Slack - A messaging app for teams who see through the Earth!
Slack Jira Integration - Easily keep issues moving right from Slack
Mattermost - Mattermost is an open source alternative to Slack.
Sortd for Slack - Get Trello-style project boards right in your Slack!
9mCollab - Collaborate (efficiently) Conclude (fast) Contribute (in the knowledge base)
Intercom - Intercom is a customer relationship management and messaging tool for web businesses. Build relationships with users to create loyal customers.