Twilio - Brings voice and messaging to your web and mobile applications.
Direct SMS - Direct SMS is an SMS API & SMS Software provider specializing in SMS services in Australia.
Nexmo - Nexmo is a simple two way SMS API with global reach and wholesale rates
TextBelt - Send text messages to any phone via Terminal!
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.
SMS Broadcast - SMS Broadcast is a bulk SMS provider and an easy way to use SMS Marketing for businesses.