Examine source code of Wonderspend Add-On

{
  "manifest_version": 2,
  "name": "Wonderspend Add-On",
  "version": "1.0.1",
  "description": "Supportive browser add-on for Wonderspend.com which notifies the end-user if he/she navigates to a website which partners with us, that he/she may benefit a cashback from the purchases made.",
  "icons": {
    "16": "dist/icons/favicon-16x16.png",
    "32": "dist/icons/favicon-32x32.png",
    "48": "dist/icons/favicon-48x48.png"
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "dist/js/content.bundle.js"
      ]
    }
  ],
  "browser_action": {
    "browser_style": true,
    "default_popup": "home.html",
    "default_icon": {
      "16": "dist/icons/favicon-16x16.png",
      "32": "dist/icons/favicon-32x32.png"
    }
  },
  "permissions": [
    "tabs",
    "activeTab",
    "cookies",
    "<all_urls>",
    "storage"
  ],
  "background": {
    "scripts": [
      "dist/js/polyfill.bundle.js",
      "dist/js/background.bundle.js"
    ]
  }
}