Twilio!

Google Voice gives you one number for all your phones, voicemail organized in an email format, free US long distance calls, low rates on international calls, and many free calling features, including transcripts, call blocking, call screening, conference calling, SMS, and more.

engageSPARK enables anyone, anywhere to build and launch SMS and Voice Call messaging, surveying, and decision tree programs to 200+ countries – within minutes. It is a self-service website where any non-technical person can easily, quickly, and cheaply create messaging campaigns, curriculums, surveys, reminders, alerts, decision tree programs, etc. to send key information and collect important data from their participants.

Plivo is a voice and SMS API platform that enables developers and enterprises to build powerful apps with great features. With 24/7 free tech support and low prices, Plivo can help your business scale globally.

Textlocal bulk SMS service allows you to quickly reach out to millions of your customers, prospects and staff within seconds at the click of a button. With our unparalleled features, you can now easily personalize your messages, attach images and PDFs, include web links as calls-to-action, send discount vouchers and coupons, and collect data via mobile forms. What’s more, you can even measure your campaign performance in real-time.

Receive & send SMS messages, allocate phone numbers, control incoming phone calls, build IVRs, connect calls and create automated outgoing phone calls. Simply Voice, SMS & MMS in one easy API.

Wazo is mainly an IPBX that provides communication services such audio, video, and instant messaging based on the use of standard network technologies such as the TCP/IP protocol. It is interoperable with most market telephony systems and gives users access to flexible and advanced services without requiring specialized hardware.

Nexmo provides innovative communication APIs that bridge traditional voice and text services with cloud communications.

CALLR is a voice and messaging API available through REST, JSON-RPC and SDKs (PHP, Python, Ruby, Go, Node.JS, Swift, Java, .NET). It's built with many features made to help brands create smarter interaction with their customers and prospects. CALLR's services are available worldwide in 220+ countries. Two web interfaces, SENDR (Campaign Management) and CALLTRACKR (calltracking and click-to-call) are available to offer access to CALLR's services without having to code.Here are our six main business use cases:SIP Trunking (Outbound and inbound calls at scale) - Conveniently handle my important outgoing call needs. Face any international needs with an adaptive solution that matches my location, and network situation.User Acquisition and Engagement (Outbound calls and SMS campaigns) - Generate online and in-store traffic and keep users engaged using automated and scalable communications methods. Easily broadcast news about sales and events to my customer base.Notifications (Personalized outbound calls and SMS) - Send personalized messages to your customers at key steps of their journey. Notify them of main events and make sure they receive your messages.Custom IVR (Inbound or outbound calls control menu) - Create a smart mapping to route incoming calls according to the rules I set. Make sure each call I receive is handled the quickest and most efficient way.Call Tracking (Inbound calls source identification) - Track incoming calls activity and know where my users found my number. Track calls generated for and routed to a third party.Person to Person Communication (Users calls and SMS safeguarding) - Easily allow my users to exchange with each other on their usual channels. Frame the interaction to ensure its security and keep it smooth. »

Voximplant is a cloud platform for developing real-time communication apps with full control over voice and video. Our cloud application engine provides developers with a way to control every call leg using JavaScript logic. Voximplant allows embedding business logic in JavaScript scenarios and reducing requirements for backend services. The JavaScript code running in our cloud provides access to text-to-speech and speech recognition, IVR, ACD, Call Lists, as well as enables third-party services to send and receive HTTP requests, and much more! Our platform has web, android, iOS and react native SDKs alongside with web-based debugging tools. »

An simple text message API.

This RESTful API is a modern API that lets you use the message services provided by iP.1 Networks AB via your own applications. Do everything from just sending SMS messages to managing contacts and sending surveys.

Spring Edge is one of the premier business communication solutions provider, Spring Edge's core services includes messaging and voice communications with comprehensive and customized platform for all business scales.

XiVO is a scalable platform based on Asterisk that offers a free and complete PBX solution. It is licensed under the GPLv3.

SMS Gateway is your bridge between the Internet and the world of cell phone SMS text messaging. We've taken care of all the complicated details and harnessed the sophisticated technology necessary to bring you a simple solution for sending SMS text messages from a web or desktop application.

Sinch is a powerful voice and messaging SDK that lets you bring your apps to life with VoIP and WebRTC technology. Simplicity is at its core and you can get your first app up and running in a few lines of code and a matter of minutes.