Examine source code of Sticker Pin

{
  "manifest_version": 2,
  "name": "Sticker Pin",
  "version": "1.0",
  "description": "Drag any image on a page to create a persistent floating sticker pinned to the viewport (survives scrolling).",
  "permissions": [
    "storage",
    "activeTab"
  ],
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "content.js"
      ],
      "css": [
        "styles.css"
      ],
      "run_at": "document_idle"
    }
  ],
  "browser_action": {
    "default_popup": "popup.html"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{51bd1ee4-7c27-4070-8895-0253ead293ee}"
    }
  }
}