A simple extension that checks for external links on a webpage that do not have the attribute rel="nofollow"
Copy the files into a folder on your computer.
In Chrome, navigate to chrome://extensions/. Make sure the 'Developer mode' checkbox has been ticked.
Click on the 'Load unpackaged extension' button, and navigate to the folder that contains these files.
Alternatively, the plugin can be installed directly from the Chrome Store
Click on the newly created browser button to show any external links on the current webpage that do not have the attribute rel="nofollow"
Auto enable for all websites
Select colour for link highlighter