Examine source code of Timezone Clock Dashboard

{
  "manifest_version": 2,
  "version": "1.0.4",
  "name": "Timezone Clocks Dashboard",
  "short_name": "clockdashboard",
  "description": "Customize your dashboard with multiple timezones",
  "icons": {
    "16": "icons/16x16.png",
    "32": "icons/32x32.png",
    "64": "icons/64x64.png",
    "128": "icons/128x128.png",
    "256": "icons/256x256.png"
  },
  "browser_action": {
    "default_popup": "popup.html",
    "browser_style": false
  },
  "background": {
    "scripts": [
      "js/background.js"
    ]
  },
  "permissions": [
    "storage"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{5f03d13f-4383-4c8d-8c49-098e166ecfc9}"
    }
  }
}