Twilio offers developers a powerful API for phone services to make and receive phone calls, and send and receive text messages. Their product allows programmers to more easily integrate various communication methods into their software and programs.
Nexmo connects your apps directly to carriers around the world. Integrate SMS and Voice messages using one simple API. Use Nexmo Verity to register users, verify transactions, and implement two factor authentication.
Plivo provides basic building block APIs in the form of Plivo XML and HTTP API, to create telephony apps, so developers can completely do away with learning the nitty-gritty of the telephony plumbing.
It adds the clarity and emotion of face-to-face communication to your brand whether you're developing for the web, iOS, or Android. We make the integration of high-quality live video a breeze so that you can focus on building a great product.
It is a cloud-based voice service and the brain behind tens of millions of devices including the Echo family of devices, FireTV, Fire Tablet, and third-party devices. You can build voice experiences, or skills, that make everyday tasks faster, easier, and more delightful for customers.