Examine source code of focuscape Website Blocker

{
  "manifest_version": 2,
  "name": "__MSG_extName__",
  "description": "__MSG_extDescription__",
  "version": "1.2.1",
  "icons": {
    "16": "icon/16.png",
    "32": "icon/32.png",
    "48": "icon/48.png",
    "96": "icon/96.png",
    "128": "icon/128.png"
  },
  "default_locale": "en",
  "permissions": [
    "storage",
    "declarativeNetRequest",
    "webNavigation",
    "alarms",
    "<all_urls>"
  ],
  "declarative_net_request": {
    "rule_resources": [
      {
        "id": "ruleset_1",
        "enabled": true,
        "path": "rules.json"
      }
    ]
  },
  "web_accessible_resources": [
    "assets/*"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{f72c5c12-6c87-4c49-8375-268a05dba244}",
      "strict_min_version": "142.0",
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      }
    }
  },
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "browser_action": {
    "default_title": "focuscape",
    "default_popup": "popup.html"
  }
}