Pulse SMS - Pulse SMS is a next-generation SMS and MMS application that is fast, secure and packed with lots of modern features as well as customization feature you cloud want.
Twilio - Brings voice and messaging to your web and mobile applications.
QKSMS - QKSMS is a beautiful communication app that offers magical texting experience.
Nexmo - Nexmo is a simple two way SMS API with global reach and wholesale rates
Textra - Textra is a seriously beautiful, feature rich SMS and MMS app.
BulkSMS - SMS messaging service provider offering two-way SMS communication services.