TextNow - TextNow is a mobile virtual network operator (MVNO) that provides a free phone service to users by using other cellular networks coverage.
Twilio - Brings voice and messaging to your web and mobile applications.
TextMe - TextMe is a free calls and messaging application at both local and international levels.
Nexmo - Nexmo is a simple two way SMS API with global reach and wholesale rates
Talk360 - Talk360 is a best-in-class communication utility that offers a convenient way to connect with loved ones globally.
BulkSMS - SMS messaging service provider offering two-way SMS communication services.