Twilio - Brings voice and messaging to your web and mobile applications.
tawk.to - tawk.to is a free live chat app that lets you monitor and chat with visitors on your website or from a free customizable page
MessageBird - Reach 7 billion phones in seconds via SMS, Chat & Voice. Try it for free and improve your communication.
Intercom - Intercom is a customer relationship management and messaging tool for web businesses. Build relationships with users to create loyal customers.
Sinch - Sinch is a powerful voice and messaging SDK that lets you bring your apps to life with VoIP and...
LiveChat - LiveChat - premium live chat software. Approach customers directly on the website, make connections and drive more sales using LiveChat.