Examine source code of Website Blocker

{
  "manifest_version": 2,
  "name": "__MSG_extensionName__",
  "version": "2.3",
  "description": "__MSG_extensionDescription__",
  "author": "Wesley Branton",
  "default_locale": "en",
  "developer": {
    "name": "Wesley Branton",
    "url": "http://addons.wesleybranton.com"
  },
  "icons": {
    "32": "icons/icon-32.png",
    "48": "icons/icon-48.png",
    "64": "icons/icon-64.png",
    "96": "icons/icon-96.png",
    "128": "icons/icon-128.png"
  },
  "browser_action": {
    "default_icon": {
      "32": "icons/icon-32.png",
      "48": "icons/icon-48.png",
      "64": "icons/icon-64.png",
      "96": "icons/icon-96.png",
      "128": "icons/icon-128.png"
    },
    "default_title": "__MSG_extensionName__"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "websiteblocker@wesleybranton.com",
      "strict_min_version": "60.0"
    }
  },
  "options_ui": {
    "browser_style": false,
    "page": "options/options.html?tab=aboutaddons"
  },
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "web_accessible_resources": [
    "/blocked/blockpage.html"
  ],
  "permissions": [
    "storage",
    "webRequest",
    "webRequestBlocking",
    "<all_urls>"
  ],
  "optional_permissions": [
    "downloads"
  ]
}