Spike - Spike solves businesses' communication chaos by bringing together email, team chat, collaborative docs, and meetings, into one feed.
Twilio - Brings voice and messaging to your web and mobile applications.
Missive - Team communication app now supporting FB, Twitter & SMS
Nexmo - Nexmo is a simple two way SMS API with global reach and wholesale rates
Front - The platform for exceptional customer service at scale.
Plivo - Plivo simplifies your customer engagement.