8x8 - 8x8's VoIP business phone systems deliver affordable, cloud-based voice, video, messaging, and call center solutions, helping you serve customers anytime, anywhere.
Nexmo - Nexmo is a simple two way SMS API with global reach and wholesale rates
Vonage - Vonage is a cloud-based all-in-one VoIP software solution designed for multiple industries such as accounting, healthcare, finance and marketing etc.
MessageBird - Reach 7 billion phones in seconds via SMS, Chat & Voice. Try it for free and improve your communication.
RingCentral - RingCentral is the leading provider of cloud-based communications and collaboration solutions for small business and enterprise companies
Plivo - Plivo simplifies your customer engagement.