Examine source code of Zenzone Protect

{
  "manifest_version": 2,
  "name": "Zen Zone Protect",
  "version": "1.3",
  "description": "Blocks access to a specified domain.",
  "permissions": [
    "webRequest",
    "webRequestBlocking",
    "storage",
    "*://*/*"
  ],
  "background": {
    "scripts": [
      "./background.js"
    ]
  },
  "browser_action": {
    "default_popup": "popup.html",
    "default_icon": {
      "16": "icons/icon.png",
      "48": "icons/icon.png",
      "128": "icons/icon.png"
    }
  },
  "optional_permissions": [
    "tabs"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{004ed0c1-42ca-4888-9604-b40b5cb0766b}"
    }
  }
}