Hi There,
As per your requirement you want following cusomization in your site:
1. add user as Joomla user in site that used facebook login to register your site
2. show extra user columns in admin K2 component and an export script to export all users into a csv file.
About our company:
We are a team of developers and designers who have more than 6 years of experience in solving all kind of coding issues. Our team is specialized in HTML/HTML5, CSS/CSS3, PHP, Wordpress, Joomla, Magento, Opencart, Prestashop, XML, Javascript, jQuery, AJAX, JSON.
We can initiate the project as early as it is awarded.
We'll provide you a dedicated resource for your project so that you can track your work effectively and efficiently.
Looking forward to work with you!