Examine source code of Smilematic

{
  "name": "Smilematic",
  "description": "Automatically redirect any Amazon links to smile.amazon.com to ensure your favorite charity always gets a donation.",
  "version": "0.0.4resigned1",
  "manifest_version": 2,
  "icons": {
    "32": "resources/images/smilematic-inactive-32.png",
    "38": "resources/images/smilematic-inactive-38.png",
    "64": "resources/images/smilematic-logo-64.png",
    "128": "resources/images/smilematic-logo-128.png",
    "256": "resources/images/smilematic-logo-256.png"
  },
  "browser_action": {
    "default_title": "Smilematic"
  },
  "applications": {
    "gecko": {
      "id": "smilematic@couponfollow.com"
    }
  },
  "background": {
    "scripts": [
      "scripts/background/urlConfig.js",
      "scripts/background/redirectConfig.js",
      "scripts/background/redirect.js",
      "scripts/background/background.js"
    ]
  },
  "content_scripts": [
    {
      "matches": [
        "http://*/*",
        "https://*/*"
      ],
      "js": [
        "scripts/contentscript/iframeHandler.js"
      ],
      "css": [
        "css/contentscript/iframeHandler.css"
      ],
      "run_at": "document_end",
      "all_frames": false
    }
  ],
  "web_accessible_resources": [
    "html/contentscript/iframe.html"
  ],
  "permissions": [
    "tabs",
    "storage",
    "webRequest",
    "webRequestBlocking",
    "*://www.amazon.com/*",
    "*://www.amazon.de/*",
    "*://www.amazon.co.uk/*"
  ]
}