I've a feeling we're not in a Sandbox anymore

manifest.json

{
  "update_url": "https://clients2.google.com/service/update2/crx",
  "author": "Steven Herod - http://limitexception.com/",
  "short_name": "Toto",
  "name": "I've a feeling we're not in a Sandbox anymore",
  "description": "Warns you that you are in a production instance of Salesforce with a noticable yellow banner",
  "version": "1.0",
  "permissions": [
    "webNavigation",
    "https://*/"
  ],
  "background": {
    "scripts": [
      "background.js",
      "prod_script.js"
    ],
    "persistent": false
  },
  "browser_action": {
    "default_title": "Toto, I've a feeling we're not in a Sandbox anymore."
  },
  "icons": {
    "128": "icon128.png"
  },
  "manifest_version": 2
}