Twilio - Brings voice and messaging to your web and mobile applications.
Infobip - A2P messaging platform for enterprises, resellers & mobile operators with global network coverage.
Nexmo - Nexmo is a simple two way SMS API with global reach and wholesale rates
ClickSend - ClickSend builds communication software and tools for businesses. We offer SMS, MMS, Voice, Email, Online Mail and even Fax. All accessed via our Dashboard, app, flexible API or integrations.
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.
Textmagic - The all-in-one solution for all your business texting needs - marketing campaigns, two-way SMS chats, reminders, notifications, and internal staff communication.