Slack - A messaging app for teams who see through the Earth!
Spokk - Get your creations or ideas for blogs, designs, art, music, photos, YouTube videos or anything...
9mCollab - Collaborate (efficiently) Conclude (fast) Contribute (in the knowledge base)
Sity - Share what you've done with your team and give feedback
Mattermost - Mattermost is an open source alternative to Slack.
Brevy (beta) - Give feedback, Google-doc style, directly on your website