Anti-Paywall is an extension for Chrome and Firefox that allows you to bypass paywall's on a selection of news sites from around the globe.
I am often frustrated when clicking on a link in Google News or on Twitter to be faced with a message saying that I need to register to read the content. This extension will help you to bypass the registration and see the full article straight away.
The extension, amongst other things, makes changes to the user agent to mask as Google Bot, cookies or referer, to bypass the paywall.
If you would like to check the source code you can visit the dev's github page. On this page you can see the full list of news sites paywall's that are bypassed by the extension.