Twilio - Brings voice and messaging to your web and mobile applications.
Upstash - Upstash provides Serverless Redis and Kafka as a service.
Nexmo - Nexmo is a simple two way SMS API with global reach and wholesale rates
restdb.io - restdb.io lets you create databases and REST APIs quickly. Development databases are free. Powerful web-based and mobile-friendly data management.
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.
PlanetScale - The last database you'll ever need. Go from idea to IPO.