Twilio - Brings voice and messaging to your web and mobile applications.
OpenTok - Build a custom video experience using our robust APIs, or add plug-and-play video to your website in minutes using Video Chat Embeds. Start Building for FreeTalk to SalesTalk to Sales .
Nexmo - Nexmo is a simple two way SMS API with global reach and wholesale rates
addlive - AddLive leverages WebRTC to allow anyone to easily add video and voice conferencing to their...
BulkSMS - SMS messaging service provider offering two-way SMS communication services.
Plivo - Plivo simplifies your customer engagement.