This simple plugin developed for developers.
Can not be used alone! yet, it does not have an end-user feature.
It completes your sms settings once and you can now use SMS functions in all WordPress.
You can add new SMS provider to inc/providers folder. Netgsm_Provider.php may be example for you! For more detail please write us: wp@gri.net
This example provider use WordPress HTTP API with GET method. Connect provider API url and processes the results.
Again it is worth mentioning, this is a developer plugin. You can’t use this plug-in as an end-user.
wp_sms_send_sms($receiver_number, $message). If this function unknowned, you can include file ABSPATH . '/wp-content/plugins/wp-sms-functions/inc/functions.php'. Including too many times will not cause problems. It will protect itself against it.