Examine source code of ImageFocus

{
  "manifest_version": 2,
  "name": "ImageFocus",
  "version": "1.0.7",
  "description": "Double-click on an image to isolate it, use the mouse wheel to zoom, drag to pan.",
  "author": "Rezzi",
  "permissions": [
    "activeTab"
  ],
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "content.js"
      ],
      "css": [
        "overlay.css"
      ]
    }
  ],
  "icons": {
    "48": "icons/icon48.png",
    "96": "icons/icon96.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "imagefocus-ext@basti.dev",
      "strict_min_version": "142.0",
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      }
    }
  }
}