Examine source code of Good Day Alert

{
  "name": "Good Day Extension",
  "version": "0.0.0.1",
  "description": "Build an Basic Extension!",
  "permissions": [
    "activeTab"
  ],
  "browser_action": {
    "default_popup": "popup.html",
    "default_icon": {
      "16": "img/hgd_icon_16.png",
      "32": "img/hgd_icon_32.png",
      "48": "img/hgd_icon_48.png"
    }
  },
  "manifest_version": 2,
  "browser_specific_settings": {
    "gecko": {
      "id": "{e8da010e-1ea7-42f6-a4d6-9cbed11ea7a4}"
    }
  }
}