Clockwork SMS - Clockwork is an Easy Text Message API. An SMS API for Developers. Build powerful apps and include SMS. Signup is free, Try it now.
Clearstream - Clearstream is a SMS marketing and online texting software.
Twilio - Brings voice and messaging to your web and mobile applications.
E-goi - Email Marketing companies, SMS Marketing, software email marketing.
Crypton.sh - SMS - Secure Anonymous SMS in the cloud (and a phone number)
Maytapi - Serverless Whatsapp Api with Chat and Agent support.