1. Download these two files to your computer.
Important: It is very important that you extracted the archive correctly.
Check that in the folder where you extracted the archive files like background.js and manifest.json were present.
If instead you see one folder, which in its turn contains these files, the extraction was incorrect.
Check the scheme below.
[folder with extracted extension] ==> [background.js, manifest.json, other files] CORRECT
[folder with extracted extension] ==> [one more folder] ==> [background.js, manifest.json and other files] WRONG
3. Open the Extensions page in your Chrome browser (Settings -> More tools -> Extensions).
4. Enable Developer mode (1) and then click Load unpacked extension… (2)
5. Go to the directory where you extracted the zip file and choose it. Click OK.
You will now have the extension installed.
Important: If you have the “Could not load manifest“ error please check that you extracted the archive correctly (see p.2).
Important: If you have the “Could not load background script 'background.js'” error, first check that you extracted the archive correctly. If you extracted it correctly and still get the error, the problem might be with your antivirus, which sometimes overreact on .js files.
6. Note that after you restart your Chrome browser, a pop-up window will appear.
Click Cancel to dismiss it.
7. If you don’t want to dismiss the above popup every time, use the following small hack.