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 in a tool-tip.
What this extension does, is look for links that appear to be direct, displaying the full URL to the user, but have a different target URL underneath. Then it replaces the link target with the URL that was shown to the user, killing tracking and analytic links that try to hide the target URL.
If you are interested in contributing to the project, or have any issues or ideas, you can find this project's GitHub repository here:
https://github.com/ShimmyMySherbet/LinkReplacer
