"Read more" plugins add another level of subscription access control to K2 items. Smart Subscriptions application core manages items (articles, modules, menu items, etc.) a user can view basing on his current active subscription. With "Read more" plugin enabled site administrator can set additional access property for K2 item (article) full text (the content after "read more").
If "Full text access" is set to a view level which is not allowed for current user, K2 item full text will be replaced by a notification with a link to registration or profile form. Subscriptions selector control on this form will only show subscriptions compatible with the article full text access. Set "Full text access" to "- Article global -" to disable full text access control for this K2 item.
When plugin is installed and enabled it will appear in "K2 plugins" tab on K2 item edit form in Joomla administration.