Examine source code of Image Zoomer

{
  "manifest_version": 2,
  "name": "Image Zoomer",
  "version": "1.2resigned1",
  "description": "Resize images inline by holding the right mouse button and dragging.",
  "icons": {
    "48": "icons/icon48.png",
    "96": "icons/icon96.png"
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "ImageZoomerMin.js"
      ]
    }
  ],
  "developer": {
    "name": "Kneels",
    "url": "www.kneels.net"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{ef6f09da-955d-45db-b9c4-b174adba0b15}"
    }
  }
}