Examine source code of Quick Save Image

{
  "manifest_version": 2,
  "name": "Quick Save Image V2",
  "version": "1.0",
  "description": "Easily save images from web pages with hover save button",
  "permissions": [
    "activeTab",
    "<all_urls>"
  ],
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "content.js"
      ]
    }
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{944f38fc-9fdb-4712-9716-363b1f91270a}"
    }
  }
}