Intercom - Intercom is a customer relationship management and messaging tool for web businesses. Build relationships with users to create loyal customers.
Nexmo - Nexmo is a simple two way SMS API with global reach and wholesale rates
Pure Chat - Pure Chat provides FREE live website support and sales chat without the hassle! It's web site chat, simplified.
MessageBird - Reach 7 billion phones in seconds via SMS, Chat & Voice. Try it for free and improve your communication.
Zendesk - Zendesk is a beautiful, lightweight help-desk solution.
Plivo - Plivo simplifies your customer engagement.