Examine source code of frens

{
  "manifest_version": 2,
  "name": "frens",
  "version": "1.4.2.2",
  "description": "Replaces bad words with good words",
  "icons": {
    "48": "kokoro8.jpg"
  },
  "permissions": [
    "activeTab"
  ],
  "content_scripts": [
    {
      "matches": [
        "*://*/*"
      ],
      "js": [
        "frens.js"
      ]
    }
  ]
}