Twinme - Twinme – Private Messenger is a free, secure, instant, and high-definition messaging app that protects your privacy along with giving you full control over each of your relationships and contents.
Twilio - Brings voice and messaging to your web and mobile applications.
Textra - Textra is a seriously beautiful, feature rich SMS and MMS app.
Plivo - Plivo simplifies your customer engagement.
Material Messaging - Material Messaging is a beautiful communication app that lets you send and receive SMS and MMS messages using the intuitive interface while giving you complete control over every aspect of your messaging experience.
MessageBird - Reach 7 billion phones in seconds via SMS, Chat & Voice. Try it for free and improve your communication.