Invoca - Call tracking & analytics software
Dialpad - Switch is a cloud-based phone system built for Google Apps users.
CallTrackingMetrics - Know who is calling and how they found you. Maximize the return on your advertising.
8x8 X Series - X Series connects teams across channels and around the globe, giving you access your most critical information securely, from any location.
Marchex - Marchex is a mobile advertising analytics company that connects online behavior to real-world, offline actions.
Nextiva - Business VoIP, cloud phone systems trusted by more than 150,000 companies. Powered by the leading cloud PBX VoIP platform, Nextiva is rated the best business VoIP service provider.