Examine source code of FokkerBlokker

{
  "manifest_version": 2,
  "name": "FokkerBlokker",
  "version": "1.0",
  "description": "Modderfokkers blokken.",
  "icons": {
    "48": "icon.png"
  },
  "browser_action": {
    "default_icon": "icon.png",
    "default_title": "FokkerBlokker",
    "default_popup": "settings/options.html"
  },
  "content_scripts": [
    {
      "matches": [
        "*://frontpage.fok.nl/*"
      ],
      "js": [
        "FokkerBlokker.js"
      ],
      "run_at": "document_end"
    }
  ],
  "permissions": [
    "storage"
  ]
}