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
Restcomm - Next generation cloud communication platform that allows for the easy building of voice, video, and messaging applications.
Plivo - Plivo simplifies your customer engagement.
Melrose Labs SMSC Simulator - SMPP SMSC simulator to test SMS messaging applications.
Infobip - A2P messaging platform for enterprises, resellers & mobile operators with global network coverage.