Category: Instant Messaging / Communications Software
Features include: File Sharing, Notifications, Search, Mobile Application, Web Application, Integrations
Initial Release: 14 August 2013
Number of active users worldwide: 12 million daily active users (as reported in 2019)
Free version available: yes
Slack gained great popularity within the tech community from its early days. Even in some communities it became the synonym for team messaging tool. It is available on both mobile and desktop devices, on all current operating systems.
You can organize different channels for your teams, have quick access to several teams and so on. Relatively recently, it started supporting video calls as well.
Although it is not intended for cloud storage, it can easily be integrated with Google Drive and Dropbox too. And in the meantime, you can share files with your team members – although for a limited number of megabytes in a free version