LoopMessage - LoopMessage is a perfect macOS tool for personalized mass messaging via iMessage/SMS, WhatsApp, Facebook Messenger, Telegram, Viber, and Skype.
Texted.io - Send text blasts to groups, receive individual replies
SuperDMs - SuperDMs helps you grow your following by sending bulk DMs to your tweet responders.
Sonar - 2-way chat with your customers over SMS and FB Messenger
Promote Route - A Better WhatsApp™ Experience
WhatsMany - Send personalised WhatsApp messages in bulk