Examine source code of SampleFocussed

{
  "manifest_version": 2,
  "name": "SampleFocussed",
  "description": "Easily download samples from SampleFocus.com without an account and limitations. Just click the download button on a sample after searching.",
  "version": "2",
  "icons": {
    "75": "icons/75.jpg"
  },
  "content_scripts": [
    {
      "matches": [
        "*://samplefocus.com/*",
        "*://*.cloudfront.net/samples/*"
      ],
      "js": [
        "samplefocussed.js"
      ]
    }
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{e120cea5-9575-4511-9bbf-3a60744502a5}"
    }
  }
}