HeySpace - HeySpace is the only free task and simple project management software with communication and collaboration feature.
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.
The New Dropbox - Enterprise software portal for team collaboration
Mattermost - Mattermost is an open source alternative to Slack.
Skarpline - Skarpline provides centralized enterprise messaging, link sharing and file management to improve productivity.