Psyced - This is psyced, a scalable multi-protocol multi-casting chat, messaging and social server solution...
ShoutOUT - All in one business texting tool to send personalized alerts, promotions, reminders, short links and marketing campaigns, for any SMEs (hotels, restaurants, education, non profits, Woocommerce, banks, healthcare, agencies, supermarkets, weddings)
Jitsi - Open-source video calling and chat platform.
Trumpia - SMS Marketing and Marketing Automation software for Mass SMS, internal communications & emergency alerts. #1 Text Messaging Service used by Fortune 500s.
MagicPad - Free, simple, and private, offline text encryption suite.
Clickatell - Simple, reliable mobile messaging cloud.