We have all liked and favorited posts on Facebook, Reddit, Twitter, and other social networking / viral sites. Thanks to Favorites for WordPress, you can add a similar type of functionality to your website. This plugin lets your visitors like your posts and add them to their list. Favorites works on any post type and can be used by registered and anonymous users.
Favorites can be easily enabled or disabled on posts, pages, and custom post types. You can customize its text and cookie options in the back-end. Updates can be saved in the session or browser cookie. You can use a template function or shortcode to display a list of user favorites on your site.
Favorites is coded with developers in mind. It has a bunch of functions to make their life easier. It is WordPress Multisite compatible.