Maytapi - Serverless Whatsapp Api with Chat and Agent support.
Swift SMS Gateway - SMS Gateway is your bridge between the Internet and the world of cell phone SMS text messaging.
Octopush - Octopush is a company providing technology-based communication solutions, including SMS, Web solutions, and Email APIs.
Ozeki NG SMS Gateway - Ozeki NG SMS Gateway is a powerful, reliable and flexible SMS Gateway application.
CheapGlobalSMS - Send instant bulk SMS worldwide, with reliable SMS delivery and reports in real-time.
Plivo - Plivo simplifies your customer engagement.