Should only those users with smartphones benefit from two-factor authentication? Authy didn’t think so, so they let users receive their tokens via a text message.
Tonight I’ve updated the Authy for WordPress plugin to support SMS-based tokens. Upgrade to version 0.2 to take advantage of this feature.
No additional plugin configuration is necessary, but Authy does ask that you have at least their free Starter plan to use this feature.
Authy for WordPress can be downloaded at http://wordpress.org/extend/plugins/authy-for-wp/ or installed/updated via the WordPress dashboard.