Mightytext - Send & Receive SMS Text Messages from your computer. Sync'd with your Android #
Jasmin SMS Gateway - Jasmin is a very complete open source SMS Gateway with many enterprise-class features such as:
Way2SMS - Way2SMS.com is an online portal based in Hyderabad, India, offering free and unlimited SMS across...
Bulk SMS Services - Sending Bulk SMS to the customers will engage the customers with your business and new offers.
Telerivet - Instant SMS & voice platform for organizations anywhere in the world.
Kannel - Open Source WAP and SMS Gateway