Examine source code of Curse Filter

{
  "manifest_version": 2,
  "name": "Foulmouth Filter",
  "version": "0.3",
  "icons": {
    "400": "icons/48.jpg"
  },
  "description": "Filters out filthy words from document titles",
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "filter.js"
      ]
    }
  ]
}