Examine source code of SmoothZoom

{
  "manifest_version": 2,
  "name": "SmoothZoom",
  "version": "1.1",
  "description": "Smooth zoom web page without touchpad",
  "homepage_url": "https://github.com/AllanChain/firefox-smooth-zoom",
  "icons": {
    "48": "icons/icon-48.png"
  },
  "developer": {
    "name": "Allan Chain",
    "url": "https://github.com/AllanChain"
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "lib/smooth-zoom.js"
      ]
    }
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "smooth-zoom@allanchain.github.io"
    }
  }
}