Microsoft Teams - Wikipedia[if lt IE 9]><![endif]
StartFragmentMicrosoft Teams is a platform that combines workplace chat, meetings, notes, and attachments. The service integrates with the company's Office 365 subscription office productivity suite, including Microsoft Office and Skype, and features extensions that can integrate with non-Microsoft productsEndFragment
We have been using MS Teams to track tasks, share notes, chat, share files, and there are tons of extra features that will help you create a collaboration package. It puts all you company collaboration in one location to share and work with your co-workers.
You need office 365 subscription to use this and it is well worth it.