Examine source code of Simple Tab Exporter

{
  "manifest_version": 2,
  "name": "Simple Tab Exporter",
  "version": "1.0.3resigned1",
  "description": "This add-on create a list of opened tabs which can be emailed for backup purposes",
  "browser_action": {
    "default_title": "Simple Tab Exporter"
  },
  "background": {
    "scripts": [
      "listener.js"
    ]
  },
  "permissions": [
    "activeTab",
    "tabs"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{66fd2dfb-459b-4363-b67b-3a2371e3d8fc}"
    }
  }
}