Twilio - Brings voice and messaging to your web and mobile applications.
Fastsms - Fastsms helps you with marketing by providing business text messaging which you can use to send information regarding discounts and delivery details to customers.
Nexmo - Nexmo is a simple two way SMS API with global reach and wholesale rates
Group Texting - Group Texting provides your business with a robust Group texting software that supports up to 10-digits numbers.
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.
Textline - Textline is SaaS software for business text messaging. Add text messaging capabilities to an existing landline, or get a new textable phone number for your business in your local area code.