Examine source code of Focus Shield

{
  "manifest_version": 2,
  "name": "Focus Shield",
  "version": "1.0.0",
  "description": "Block distracting websites and track your productivity with customizable focus sessions and website blocking",
  "permissions": [
    "activeTab",
    "webRequest",
    "webRequestBlocking",
    "<all_urls>",
    "alarms",
    "storage"
  ],
  "background": {
    "scripts": [
      "background.js"
    ],
    "persistent": true
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "content.js"
      ],
      "css": [
        "content.css"
      ]
    }
  ],
  "browser_action": {
    "default_popup": "popup.html",
    "default_title": "Focus Shield"
  },
  "icons": {
    "16": "icons/icon-16.png",
    "48": "icons/icon-48.png",
    "128": "icons/icon-128.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{6e088857-1e5d-46a2-b9e2-0c2e95203599}"
    }
  }
}