Examine source code of Nein Tabs

{
  "manifest_version": 2,
  "name": "Nein Tabs",
  "description": "Say nein to too many tabs.",
  "version": "1.0.2resigned1",
  "author": "Christoph Gockel",
  "background": {
    "scripts": [
      "nein.js"
    ],
    "persistent": false
  },
  "icons": {
    "16": "icons/16.png",
    "48": "icons/48.png",
    "64": "icons/64.png",
    "128": "icons/128.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{94e2e4d6-bfda-4ff2-8592-ee74774180eb}"
    }
  }
}