Pulse SMS - Pulse SMS is a next-generation SMS and MMS application that is fast, secure and packed with lots of modern features as well as customization feature you cloud want.
Twilio - Brings voice and messaging to your web and mobile applications.
QKSMS - QKSMS is a beautiful communication app that offers magical texting experience.
Bandwidth - Bandwidth offers SIP trunking, Emergency communications, and Voice & Messaging APIs.
Textra - Textra is a seriously beautiful, feature rich SMS and MMS app.
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.