Spike.sh - Spike is an incident management platform that alerts via slack, phone and email and automatic escalations to help teams fix infrastructure problems.
WhatsMany - Send personalised WhatsApp messages in bulk
Sendblue - Programmatically send iMessage and SMS
LoopMessage - LoopMessage is a perfect macOS tool for personalized mass messaging via iMessage/SMS, WhatsApp, Facebook Messenger, Telegram, Viber, and Skype.
Clerk - Clerk.io, the artificial intelligence for e-commerce that knows your customers interests.
Porterhouse - Send mass iMessage and SMS texts from your existing number with a single click!