SMS Alert for Contact Form 7 is a plugin for the popular contact form 7. So this is an extension for the CF7 plugin to send SMS alert. This plugin can send SMS to both admin and user.
This plugin uses SMS API. There are four SMS API uses in this plugin. These are
Twilio,
Nexmo,
MSG91,
Textlocal.
In case of MSG91 SMS API, you must have to buy the transactional SMS plan.