Examine source code of Taggem

{
  "manifest_version": 2,
  "name": "Taggem",
  "version": "0.1.0",
  "description": "Add a multiple tags directly to the URL of websites",
  "icons": {
    "16": "assets/taggem-logo-16.png",
    "48": "assets/taggem-logo-48.png",
    "128": "assets/taggem-logo-128.png"
  },
  "web_accessible_resources": [
    "assets/taggem-logo-48.png",
    "assets/ok-128.png",
    "assets/delete-64.png"
  ],
  "browser_action": {
    "default_icon": "assets/taggem-logo-16.png",
    "default_popup": "popup.html"
  },
  "options_ui": {
    "page": "options.html"
  },
  "background": {
    "scripts": [
      "scripts/tabListener.js"
    ],
    "persistent": false
  },
  "permissions": [
    "activeTab",
    "storage",
    "tabs"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{f5b8a772-6e96-43db-97d7-9d5f89d427d8}"
    }
  }
}