Examine source code of CookieSwap

{
  "manifest_version": 2,
  "name": "__MSG_appname__",
  "version": "1.3",
  "description": "__MSG_appdesc__",
  "default_locale": "en",
  "icons": {
    "16": "img/icon16.png",
    "32": "img/icon32.png"
  },
  "browser_action": {
    "default_icon": {
      "16": "img/icon16.png"
    },
    "default_title": "__MSG_appdesc__",
    "default_popup": "popup.html"
  },
  "permissions": [
    "tabs",
    "<all_urls>",
    "storage",
    "cookies",
    "browsingData",
    "downloads"
  ],
  "background": {
    "scripts": [
      "js/background.js"
    ]
  },
  "browser_specific_settings": {
    "gecko": {
      "strict_min_version": "57.0",
      "id": "{27cbfa9e-ffcc-4c90-8937-10a22fe21427}"
    }
  }
}