MessageBird - Reach 7 billion phones in seconds via SMS, Chat & Voice. Try it for free and improve your communication.
Nexmo - Nexmo is a simple two way SMS API with global reach and wholesale rates
Plivo - Plivo simplifies your customer engagement.
Sinch - Sinch is a powerful voice and messaging SDK that lets you bring your apps to life with VoIP and...
Bandwidth - Bandwidth offers SIP trunking, Emergency communications, and Voice & Messaging APIs.
BulkSMS - SMS messaging service provider offering two-way SMS communication services.