Protonet - Private cloud servers - Slack meets Dropbox in a box
Nexmo - Nexmo is a simple two way SMS API with global reach and wholesale rates
Duple - Create your own private cloud at home
MessageBird - Reach 7 billion phones in seconds via SMS, Chat & Voice. Try it for free and improve your communication.
Convox - A year ago, I described a strategy we use to build Convox: Integration over Invention. This philosophy leads us to build a platform that integrates existing cloud services instead of building custom software.
Plivo - Plivo simplifies your customer engagement.