Examine source code of Amazon Link Cleaner

{
  "manifest_version": 2,
  "name": "Amazon Link Cleaner",
  "version": "1.1",
  "description": "Automatically redirects Amazon links to their shortest versions for more privacy and easier sharing.",
  "permissions": [
    "webRequest",
    "webRequestBlocking",
    "tabs",
    "*://www.amazon.com/*"
  ],
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "icons": {
    "48": "icon.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{f5e71956-388a-4c54-a942-5e9fc5dec3b7}"
    }
  }
}