Examine source code of heiLOW

{
  "manifest_version": 2,
  "name": "heiLOW",
  "version": "1.2",
  "icons": {
    "48": "icons/icon.png",
    "96": "icons/icon96.png"
  },
  "description": "Replaces all 'hei' with 'low', and includes other text substitutions to improve browsing experience on a multitude of sites.",
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "heilow.js"
      ]
    }
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{e2d21d27-3910-42b0-b5fa-2c5b03790ced}"
    }
  }
}