This is a browser add-on that copies True Link URL as shown at the status bar.
When you hover on a link the browser shows its URL at the status bar. But a lot of sites are faking this info. That is, if you will click on the link or copy its URL then you will get not what displayed at the status bar.
This add-on adds new context menu item called "Copy True Link". By pressing it, the actual URL (as displayed at the status bar) will be copied to your clipboard.
https://addons.mozilla.org/en-US/firefox/addon/copy-true-link/
https://chrome.google.com/webstore/detail/copy-true-link/mcpokcikbbfcdogkpaebcekojhphhlfc