Extensions that start with the letter V, are Free and are sorted by Edit Date.
Adds the ability to create custom fields designed to store URLs, with the addition of ajax URL validation. Supports Matrix and Low Variables.
This extension just logs more stuff to control panel log (Tools > Logs > Control Panel Log).
Uses the open-source Bad Behavior script to block potential spammers, not only from submitting forms, but from even seeing your website.
The View Counts extension displays the view counts for entries in the edit page list in the control panel.
This extension allows you to add youtube and googlevideo to Expression Engine forum posts.