Examine source code of Popup Tooltip

{
  "manifest_version": 2,
  "name": "Popup Tooltip",
  "version": "1.2",
  "description": "Popup tooltip when highlighting text on a page for search, maps etc..",
  "icons": {
    "48": "icons/egg2.png"
  },
  "permissions": [
    "clipboardWrite",
    "storage"
  ],
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "css": [
        "popup.css"
      ],
      "js": [
        "popup.js"
      ]
    }
  ],
  "options_ui": {
    "page": "options.html"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "popup_tooltip_2@example.com"
    }
  },
  "browser_action": {
    "default_icon": "icons/egg2.png",
    "default_title": "Popup Tooltip",
    "default_popup": "options.html"
  }
}