Many websites and emails use tracking links behind seemingly direct-looking links. This can rarely be for user safety, to pre-screen external URLs. However, the majority of the time it is for tracking and analytics. You can spot these links before you even click on them, as when you hover over them with your mouse, a different, usually longer link is displayed.
This extension looks for links that appear to be direct, displaying a full URL to the user, but have a different target URL. Then this extension replaces the link target with the URL that was shown to the user, killing tracking and analytic links you common recieve in emails or sites that have user generated content.
You can install this extension from the Mozilla web store: https://addons.mozilla.org/en-US/firefox/addon/linkreplacer/
A version for chrome may be released in the future if there is demand.