Twilio - Brings voice and messaging to your web and mobile applications.
DialMyCalls - The easy to use mass and emergency notification platform. Send a phone call, text message or e-mail to your entire list of people in seconds.
Nexmo - Nexmo is a simple two way SMS API with global reach and wholesale rates
Signal Vine - Signal Vine is a texting solution that gives higher education institutions the power to boost enrollment, retention, and graduation rates through messaging.
Clockwork SMS - Clockwork is an Easy Text Message API. An SMS API for Developers. Build powerful apps and include SMS. Signup is free, Try it now.
STARS Campus for Career Colleges - STARS Campus Solutions is a web-based campus management system that brings a comprehensive approach to student contact management.