Attached are the versions of the Chrome and Firefox extensions as of July 2018.

To install these offline:

  1. Firefox: To install an extension manually, download the XPI file, then open Firefox and select 'Add-ons' from the menu. Drag and drop the downloaded file onto the list of currently available extensions. Click 'Install', then restart your browser when prompted to activate the extension.
  2. Chrome: Go to chrome://extensions/ and check the box for Developer mode in the top right. Use a CRX Extractor service  to unpack the CRX file and turn it into a ZIP file. Locate the ZIP file on your computer and unzip it. Go back to the chrome://extensions/ page and click the Load unpacked extension button and select the unzipped folder for your extension to install it.