Examine source code of PhotoShow

{
  "manifest_version": 2,
  "name": "PhotoShow",
  "version": "1.0",
  "description": "Show an enlarged, high-definition version of an image on hover.",
  "permissions": [
    "<all_urls>"
  ],
  "content_scripts": [
    {
      "matches": [
        "https://*/*",
        "http://*/*"
      ],
      "js": [
        "content.js"
      ],
      "css": [
        "styles.css"
      ]
    }
  ],
  "browser_action": {
    "default_popup": "popup.html",
    "default_icon": {
      "16": "icons/icon16.png",
      "48": "icons/icon48.png",
      "128": "icons/icon128.png"
    }
  },
  "icons": {
    "16": "icons/icon16.png",
    "48": "icons/icon48.png",
    "128": "icons/icon128.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{e29fee66-6029-4b5d-af2a-516da9886fc9}"
    }
  }
}