Examine source code of FireCrack

{
  "name": "FireCrack",
  "version": "1.1",
  "description": "Fixes Cracked styling for firefox",
  "permissions": [
    "activeTab"
  ],
  "content_scripts": [
    {
      "js": [
        "content.js"
      ],
      "matches": [
        "*://www.cracked.com/*"
      ]
    }
  ],
  "manifest_version": 2
}