MessageBird Chat API - Connect with your customers through different messaging apps
Twilio Flex - The programmable contact center platform 📱
Wavecell - Wavecell simplifies real-time cloud communications using SMS, Chat Apps, Video Interaction and Voice solutions.
Twilio - Brings voice and messaging to your web and mobile applications.
MessageBird API on StdLib - Purchase numbers, send SMS and more with one line of code
LoopMessage - LoopMessage is a perfect macOS tool for personalized mass messaging via iMessage/SMS, WhatsApp, Facebook Messenger, Telegram, Viber, and Skype.