Examine source code of Amazon Keep Smiling

{
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "description": "Automatically use your FREE Donation for every Amazon Purchase!",
  "icons": {
    "128": "smileyExtensionIcon.png"
  },
  "manifest_version": 2,
  "name": "Amazon Keep Smiling",
  "short_name": "Always Smile",
  "permissions": [
    "webRequest",
    "webRequestBlocking",
    "https://www.amazon.com/*",
    "http://www.amazon.com/*",
    "https://www.amazon.co.uk/*",
    "http://www.amazon.co.uk/*",
    "https://www.amazon.de/*",
    "http://www.amazon.de/*",
    "https://smile.amazon.com/*",
    "http://smile.amazon.com/*",
    "https://smile.amazon.co.uk/*",
    "http://smile.amazon.co.uk/*",
    "https://smile.amazon.de/*",
    "http://smile.amazon.de/*"
  ],
  "version": "1.0.2resigned1",
  "author": "Connor Elliott",
  "browser_specific_settings": {
    "gecko": {
      "id": "{087be7e2-7033-4740-9122-c695869b8875}"
    }
  }
}