LoopMessage - LoopMessage is a perfect macOS tool for personalized mass messaging via iMessage/SMS, WhatsApp, Facebook Messenger, Telegram, Viber, and Skype.
Telnyx SMS API - Build global text messaging right in your app
WhatsMany - Send personalised WhatsApp messages in bulk
Pragma - The home base for Ethereum developers.
Promote Route - A Better WhatsApp™ Experience
Slack RTM API - Slack's Real Time Messaging API