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.

Voxbone - Fully compliant, enterprise-ready voice and SMS on demand. Build local presence on a global scale with elastic SIP trunks and phone numbers. Try for free.

Mobiniti - Mobiniti offers a mobile marketing platform for clients to invite customers to engage with their brand through SMS via their mobile phone.

Twilio - Brings voice and messaging to your web and mobile applications.

CallHub - Predictive Call Center, Voice and Text Broadcasting app

Bandwidth - Bandwidth offers SIP trunking, Emergency communications, and Voice & Messaging APIs.