Examine source code of MoodExporter

{
  "manifest_version": 2,
  "name": "__MSG_extensionName__",
  "version": "1.0",
  "description": "__MSG_extensionDescription__",
  "permissions": [
    "storage"
  ],
  "icons": {
    "48": "icons/icon.png",
    "96": "icons/icon@2x.png"
  },
  "browser_action": {
    "default_popup": "popup.html",
    "default_icon": "icons/icon.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{cf367cbc-d795-4256-ab69-6f11ea9fe23f}"
    }
  }
}