This page shows information about a web page, and who has bookmarked it and when

https://addons.mozilla.org/en-US/firefox/addon/59

These are the public entries for this link:

• User Agent Switcher
  This is useful to see if a page is cloaking, but obviously, only if it’s cloaking at the user-agent level (vs. for instance, by IP address). Simply add the user agents you want to check out (for instance Googlebot, MSNbot, or Slurp) and then select that
  By shuqian2222 in Public bookmarks with system:unfiled
• User Agent Switcher :: Firefox Add-ons
  Firefox addon
  By wilbau in Public bookmarks with user-agent
• User Agent Switcher :: Firefox Add-ons
  By clubdebit in Public bookmarks with firefox plugin

NB: The average rating is calculated using the rating for both public and private entries for this link.