Marketing outreach on mobile devices is nothing new but finding a free, turnkey solution can sometimes be challenge. For the past few months, I have been using a neat WordPress plugin for sending mobile alerts to subscribers. Easy SMS works quite well and is easy to configure and use.
Users simply enter their phone number, carrier and once confirmed (via text message authorization), they are indexed to receive updates. From there, you can send SMS messages to groups with options to test and schedule alerts. The dashboard also offers a high level of stats, so that you can measure your outreach efforts as well as do basic list management. All you have to do is use the shortcode to embed the form on any post or page and you’re good to go. It also has the presets for 80+ carriers, with much room for adding new carriers as well as editing the carrier details.
For more specs and a full list of features, follow this link: http://wordpress.org/extend/plugins/easysms/