Twilio - Brings voice and messaging to your web and mobile applications.
MessageBird - Reach 7 billion phones in seconds via SMS, Chat & Voice. Try it for free and improve your communication.
Swift SMS Gateway - SMS Gateway is your bridge between the Internet and the world of cell phone SMS text messaging.
Nexmo - Nexmo is a simple two way SMS API with global reach and wholesale rates
Maytapi - Serverless Whatsapp Api with Chat and Agent support.
MirrorFly - World's Most Scalable Voice, Video & Chat SDK for Small, Medium & Enterprises