Twilio - Brings voice and messaging to your web and mobile applications.
Plum DEV - Plum DEV lets you use VoiceXML to build IVR and voice apps on a secure, reliable, scalable, feature-packed cloud platform.
Plivo - Plivo simplifies your customer engagement.
Genesys - Genesys provides omnichannel customer experience and contact center solutions in the cloud and on-premises.
smooch - Smooch connects your business software to all the world’s messaging channels for a more human customer experience.
Five9 - Five9 provides cloud-based call center software for sales, marketing and support.