TextMe sends a carbon-copy of all admin emails via a SMS text-message to a specified phone number.
Technically, yes. All standard carrier text-messaging fees still apply. If you are charged for receiving text messages, you will be charged for receiving text messages from TextMe. Normally, if you have an unlimited texting plan, you will not be charged anything by your carrier for that single text.
TextMe utilizes a email-to-SMS service that all of the supported carriers provide. If you are able to find this service for your unsupported carrier, it will be happily implemented. Visit the homepage of this plugin to tell me about it.