Slack is one of those apps that you use and then wonder how you ever worked without it. The developers at Slack have successfully taken communication and collaboration to an entirely new level. And you're not stuck with just one method of communicating, in fact, the entire application is designed to give you the versatility that you need to have remote conversations with a group of people, or private secure messages with only one member.
Slack is great for keeping up with your team's progress on projects and replacing emails, however, you can also collaborate with vendors and contractors, while also sharing files and documents right inside the slack app.
Managing and Tracking Documents