Examine source code of GlobeCash

{
  "manifest_version": 2,
  "name": "GlobeCash",
  "version": "1.0",
  "description": "Convert currencies and track exchange rates with ease.",
  "icons": {
    "48": "icons/globecash-48.png",
    "96": "icons/globecash-96.png"
  },
  "permissions": [
    "storage",
    "alarms",
    "https://api.exchangerate-api.com/"
  ],
  "browser_action": {
    "default_icon": "icons/globecash-48.png",
    "default_title": "GlobeCash",
    "default_popup": "popup/popup.html"
  },
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "options_ui": {
    "page": "options/options.html",
    "open_in_tab": true
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{ed3c1579-d51b-46ad-9292-dff023fb169f}"
    }
  }
}