Twilio - Brings voice and messaging to your web and mobile applications.
Swift SMS Gateway - SMS Gateway is your bridge between the Internet and the world of cell phone SMS text messaging.
Plivo - Plivo simplifies your customer engagement.
Ozeki NG SMS Gateway - Ozeki NG SMS Gateway is a powerful, reliable and flexible SMS Gateway application.
MessageBird - Reach 7 billion phones in seconds via SMS, Chat & Voice. Try it for free and improve your communication.
Bandwidth - Bandwidth offers SIP trunking, Emergency communications, and Voice & Messaging APIs.