Twilio - Brings voice and messaging to your web and mobile applications.
MirrorFly - World's Most Scalable Voice, Video & Chat SDK for Small, Medium & Enterprises
Plivo - Plivo simplifies your customer engagement.
SightCall - SightCall offers comprehensive real-time video APIs and Mobile SDKs that makes it simple to embed...
MessageBird - Reach 7 billion phones in seconds via SMS, Chat & Voice. Try it for free and improve your communication.
Nexmo - Nexmo is a simple two way SMS API with global reach and wholesale rates