The package take advantage the existing Joomla! 2FA feature by adding an additional authentication method during login, where user can secure his account with OTP (One-Time-Password) via SMS.
By following this approach we ensure full compatibility and integration with your site, regardless of the template used. That means the look and feel will be the same as the rest of your site, without the need to add something new.
Also it is part of any current, or future Joomla! feature, or security fix related with Two Factor Authentication. For example you can enforce all your users to use Two Factor Authentication from Users:Options