SendHub - Get a business phone system on your smartphone and computer. We provide professional, affordable sms, text, and voice solutions in an easy to use system. 14-day free trial.

Dialpad - Switch is a cloud-based phone system built for Google Apps users.

Mobiniti - Mobiniti offers a mobile marketing platform for clients to invite customers to engage with their brand through SMS via their mobile phone.

Asterisk - An open source telephony switching and private branch exchange service for Linux.

CallHub - Predictive Call Center, Voice and Text Broadcasting app

Cloud Telephony - Cloud Telephony delivers automated telephone applications to any phone, any place, anytime.