atonyk

This plugin adds the ‘Like’ button and ‘Who Likes’ list to:
<ul>
<li>WordPress posts and comments</li>
<li>BuddyPress activities and comments</li>
<li>BBPress posts</li>
</ul>
It allows for registered users to like the items. And it shows for both registered and unregistered users the existing likes.
The components to show the likes to can be configured on the settings page. For example, the likes can be disabled for WordPress comments.
Likes are saved in the internal WordPress and BuddyPress meta tables. No separate tables are created.
The plugin cleans all its data on uninstallation (but not on deactivation).
You can contribute on – <a href="https://github.com/ansnap/like-and-who-likes" rel="nofollow ugc">https://github.com/ansnap/like-and-who-likes</a>

Like And Who Likes

Adds the 'Like' button and 'Who Likes' list for WordPress, BuddyPress and BBPress.

Leo Baiano

Nícholas André

This plugin includes posts in the user option to inform the post content helped or not. It is suitable for use on blogs and websites that publish tutorials and recipes that help users.
<h4>Contribute</h4>
You can contribute to the source code in our <a href="https://github.com/leobaiano/post-useful" rel="nofollow ugc">GitHub</a> page.

Post Useful

Allows users to enter if the post is useful or not.

Like And Who Likes vs Post Useful