Cloudboard is a plugin that changes the look of the Admin Panel and adds some useful stuff. .

Lightweight AJAX chat.

Allows users to log in on mobile devices using a QR code.

Compares changes to the MyBB database structure and core files.

Assigns a Gravatar's randomly-generated abstract as an avatar on signup.

Formats code snippets.

Executes programmable moderation actions based on content quality.

User can only register using invite code.

Certain users groups can only view the first post of threads in certain forums.

Adds an advertisements manager to your MyBB installation.

Certain groups can leave a reply to reputation given to them.

Logs who downloads attachments.

Displays the list of user groups on index page.

This plugin allows you set which groups can't execute certain actions and/or view certain files.

Allows admins to generate coupon codes to offer discounts for services.

This plugin enhances your forum security and prevents data loss.

Count someone's posts since a certain date.

Users require minimum reputation to be able to post in certain forums.

Allows admins to make certain users' IP disappear from the logs.

This plugin allows users to set a custom status which appears on index, profile and posts.