CallFire - Grow your business with virtual phone numbers, IVR, voice broadcasting, mass text messaging services and power dialing.
Invoca - Call tracking & analytics software
CallTrackingMetrics - Know who is calling and how they found you. Maximize the return on your advertising.
RingDNA - RingDNA is a provider of cloud based inside sales productivity and marketing intelligence software such as call tracking, dialers, and IVR.
DialogTech - DialogTech is an end-to-end call attribution and conversion platform.
Marchex - Marchex is a mobile advertising analytics company that connects online behavior to real-world, offline actions.