Clearstream - Clearstream is a SMS marketing and online texting software.
Twilio - Brings voice and messaging to your web and mobile applications.
Maytapi - Serverless Whatsapp Api with Chat and Agent support.
Plivo - Plivo simplifies your customer engagement.
Octopush - Octopush is a company providing technology-based communication solutions, including SMS, Web solutions, and Email APIs.
smooch - Smooch connects your business software to all the world’s messaging channels for a more human customer experience.