Twilio - Brings voice and messaging to your web and mobile applications.
Octopush - Octopush is a company providing technology-based communication solutions, including SMS, Web solutions, and Email APIs.
Nexmo - Nexmo is a simple two way SMS API with global reach and wholesale rates
E-goi - Email Marketing companies, SMS Marketing, software email marketing.
BulkSMS - SMS messaging service provider offering two-way SMS communication services.
CheapGlobalSMS - Send instant bulk SMS worldwide, with reliable SMS delivery and reports in real-time.