Voxer - Turn your phone into a Walkie Talkie. Don't waste time on phone calls and voicemails.
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.
NextPlane - NextPlane offers cloud-based, scalable unified communications federation service for the enterprise.
MS SharePoint - Share, organize, and discover information with Microsoft SharePoint. Learn about SharePoint Online, OneDrive for Business, and Apps for SharePoint
Sameroom - Chat interoperability-as-a-service
Communifire - Enterprise Social Collaboration Software