Slack - A messaging app for teams who see through the Earth!
Dialogs by Slack - Build interactive forms in Slack that do all sorts of things
9mCollab - Collaborate (efficiently) Conclude (fast) Contribute (in the knowledge base)
Slack Voice Chat by Standuply - Easily record and send voice messages on Slack 🗣️
IntouchApp - Universal contacts manager for mobile.
Mattermost - Mattermost is an open source alternative to Slack.