Twilio - Brings voice and messaging to your web and mobile applications.
Bandwidth - Bandwidth offers SIP trunking, Emergency communications, and Voice & Messaging APIs.
Nexmo - Nexmo is a simple two way SMS API with global reach and wholesale rates
MessageBird - Reach 7 billion phones in seconds via SMS, Chat & Voice. Try it for free and improve your communication.
BulkSMS - SMS messaging service provider offering two-way SMS communication services.
Podium - Podium helps your business get more customer reviews, manage customer feedback, customer interaction, and online review management from one software.