Octopush - Octopush is a company providing technology-based communication solutions, including SMS, Web solutions, and Email APIs.
Twilio - Brings voice and messaging to your web and mobile applications.
E-goi - Email Marketing companies, SMS Marketing, software email marketing.
Plivo - Plivo simplifies your customer engagement.
Maytapi - Serverless Whatsapp Api with Chat and Agent support.
Nexmo - Nexmo is a simple two way SMS API with global reach and wholesale rates