Examine source code of Gulpease Index

{
  "manifest_version": 2,
  "name": "Gulpease Index",
  "description": "Get in the contextmenu the Gulpease index value for your text!",
  "version": "1.0.3resigned1",
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "permissions": [
    "contextMenus"
  ],
  "icons": {
    "16": "icons/page-16.png",
    "32": "icons/page-32.png",
    "48": "icons/page-48.png"
  },
  "content_scripts": [
    {
      "js": [
        "content-script.js"
      ],
      "matches": [
        "<all_urls>"
      ]
    }
  ],
  "web_accessible_resources": [
    "content-script"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{3eb2edfa-e870-4e00-b50d-0a598f8c021e}"
    }
  }
}