Examine source code of TZ Clock

{
  "manifest_version": 2,
  "name": "TZ Clock",
  "short_name": "TZ Clock",
  "description": "Calendar and clock showing multiple time zones",
  "version": "0.1.4resigned1",
  "options_ui": {
    "page": "options.html"
  },
  "browser_action": {
    "default_icon": "icons/icon.png",
    "default_popup": "popup.html"
  },
  "icons": {
    "16": "icons/icon16.png",
    "48": "icons/icon48.png",
    "128": "icons/icon128.png"
  },
  "applications": {
    "gecko": {
      "id": "tzclock@kamrik.org"
    }
  },
  "permissions": [
    "storage"
  ]
}