bbPress Thanks is a WordPress plugin that works with bbPress forums. It places a text area field in the forms used to create a new topic or reply or edit an existing one. Content entered here is hidden from users and only visible when they thank the content, click a Thanks button.
The user who authored the content and moderators can always see the content.

Flow

Basically, the flow is as follows:

1. A user enters hidden content using the topic or reply forms
2. Another user sees the topic or reply. Content is not directly shown in the topic or reply, but instead, a message stating that there’s hidden content plus a Thanks button is shown.
3. User clicks the Thanks button
4. Content is revealed for this user
5. User is added to the list of thanking users

See the screenshots for more details.

Features

• textarea element for topic and reply forms to enter the hidden content
• hidden content entered by users is only visible to themselves, moderators and other forum participants that show appreciation by clicking the Thanks button
• option to load the page with any hidden content initially collapsed and an arrow to expand and view it
• display a few user names and put the rest in a collapsible area
• or show only how many users thanked the content, without user names
• name displayed is what users select in User Profile > Display Name
• meta box in topic or reply editing screen in WP Admin to edit the hidden content
• customize colors from plugin settings page using visual controls
• enter Custom CSS in settings page to closely match your site’s appearance
• developers can take advantage of the WordPress filters and Javascript event included
• font icons that look great in normal and high density displays like Retina display
• support for Right-to-Left (RTL) languages
• complete documentation
• friendly and experienced support

Access the support forum

If you need help with customization, come to the support forums!

See Also

Allground – Responsive Fullscreen Backgrounds for WordPress

Alldion – Responsive Accordion for WordPress

Rotating Tabs Widget for WordPress