Nexmo - Nexmo is a simple two way SMS API with global reach and wholesale rates
Daily.co for Intercom - Free video calls & screen shares embedded in Intercom
MessageBird - Reach 7 billion phones in seconds via SMS, Chat & Voice. Try it for free and improve your communication.
WhatsApp - WhatsApp Messenger: More than 1 billion people in over 180 countries use WhatsApp to stay in touch with friends and family, anytime and anywhere.
Plivo - Plivo simplifies your customer engagement.
CallKite - Your website’s video call center in just one click.