Twilio - Brings voice and messaging to your web and mobile applications.
Nexmo - Nexmo is a simple two way SMS API with global reach and wholesale rates
Plivo - Plivo simplifies your customer engagement.
SendSMSGate - ✅Send SMS Bulk and 📨📨📨 Service SMS and Viber ads all over the world. 💰Cheap rices, round-the-clock support and direct contracts with mobile operators.
Tellephant - Helping you build incredible chatbots and integrate WhatsApp, Google, Facebook, SMS and more to your communication stack in seconds. All at the cheapest rates out there.
HeyWire - Next-level customer service is just a text message away.