CodeAndReload

Allows admins other users with a specially-defined user-capability to define a custom menu on the admin-bar of his or her favorite shortcuts.
<h3>Support</h3>
Technical support for this plugin will be provided via the WordPress plugin forum. Additional support may be 
available at <a href="http://www.codeandreload.com/wp-plugins/admin-bookmarks/" title="Admin Bookmarks at Code
and Reload">plugin’s homepage</a>.

Custom Admin-Bar Favorites

Allows admins other users with a specially-defined user-capability to define a custom menu on the admin-bar of his or her favorite shortcuts.

Huseyin Berberoglu

Allows users to add favorite posts. This plugin use cookies and database for 
saving data.
<ul>
<li>If a user logged in then favorites data will saved in database instead of cookies.</li>
<li>If user not logged in data will saved in cookies.</li>
</ul>
You can choose “only registered users can favorite a post” option, if you want. 
Also there is a widget named “Most Favorited Posts”. And you can use this template 
tag for listing most favorited posts;
Most Favorited Posts
If you use WP Super Cache you must add page (which you show favorites) URI to “Accepted Filenames & 
Rejected URIs”.
If you need support <a href="https://wordpress.org/support/plugin/wp-favorite-posts" rel="ugc">create a topic on support forum</a>
Please submit your pull requests to https://github.com/hberberoglu/wp-favorite-posts

WP Favorite Posts

Allows visitors to add favorite posts. This plugin use cookies for saving data so
unregistered users can favorite a post.

Custom Admin-Bar Favorites vs WP Favorite Posts