Examine source code of Simple Web Compare v2

{
  "manifest_version": 2,
  "name": "Simple Web Compare",
  "version": "1.0",
  "description": "Compare the content of two web pages and analyze similarities.",
  "icons": {
    "48": "icon.png"
  },
  "permissions": [
    "activeTab",
    "tabs",
    "storage"
  ],
  "browser_action": {
    "default_popup": "popup.html",
    "default_icon": "icon.png"
  },
  "background": {
    "scripts": [
      "popup.js"
    ],
    "persistent": false
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{dfd0135f-d342-4d39-8bb1-957f828f4b07}"
    }
  }
}