Confluence - Confluence is content collaboration software that changes how modern teams work
Slack - A messaging app for teams who see through the Earth!
Telegram - Telegram is a messaging app with a focus on speed and security. It’s superfast, simple and free.
Yammer - Yammer is a leading enterprise social network used by more than 200,000 companies worldwide, including 85% of the Fortune 500, to get work done smarter and faster. Sign Up Today.
Mattermost - Mattermost is an open source alternative to Slack.
Dropbox - Online Sync and File Sharing