Examine source code of Card exchange icon

{
  "manifest_version": 2,
  "name": "Card exchange icon",
  "version": "1.0",
  "description": "The card swap symbol is commonly used to represent the action of converting, swapping, or trading between two cards – be it a bank card, game card, customer card, or phone card code.",
  "icons": {
    "48": "icon.png"
  },
  "browser_action": {
    "default_icon": "icon.png",
    "default_popup": "popup.html",
    "default_title": "Click me!"
  },
  "permissions": [
    "activeTab"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{93dd2e9c-339a-4d80-98a1-958a99acdfd5}"
    }
  }
}