Intercom - Intercom is a customer relationship management and messaging tool for web businesses. Build relationships with users to create loyal customers.
SendSMS.global - SMS Marketing Platform
Intercom Facebook integration - Read, manage & respond to Facebook messages from Intercom
ChatWhale - Gamify your customer communication and loyalty rewards
Crypton.sh - SMS - Secure Anonymous SMS in the cloud (and a phone number)
Hubtype - Let your customers reach you through instant messaging apps