Mobiniti - Mobiniti offers a mobile marketing platform for clients to invite customers to engage with their brand through SMS via their mobile phone.
Avochato - Text messaging for your business.
SendHub - Get a business phone system on your smartphone and computer. We provide professional, affordable sms, text, and voice solutions in an easy to use system. 14-day free trial.
Postscript - Like Mailchimp for SMS
CallHub - Predictive Call Center, Voice and Text Broadcasting app
GetChat.App - Add WhatsApp chat to your website for free