Examine source code of Kiosk Link Blocker

{
  "manifest_version": 2,
  "name": "Kiosk Link Blocker",
  "version": "1.4",
  "description": "Kisok mode link blocker, prevent users visiting linked pages.",
  "background": {
    "scripts": [
      "blocker-background.js"
    ]
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "kiosk-block.js"
      ],
      "run_at": "document_start"
    }
  ],
  "permissions": [
    "webRequest",
    "tabs",
    "activeTab",
    "storage",
    "webRequestBlocking",
    "<all_urls>"
  ],
  "options_ui": {
    "page": "options/blocker-options.html",
    "browser_style": true
  }
}