Examine source code of BlurPage

{
  "manifest_version": 2,
  "name": "BlurPage",
  "description": "Blur any elements or paragraphs on page",
  "author": "Phuoc Nguyen",
  "version": "1.0.1",
  "homepage_url": "https://blur.page",
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "js/blur.js",
        "js/content.js"
      ],
      "css": [
        "css/blur.css"
      ],
      "run_at": "document_end"
    }
  ],
  "background": {
    "scripts": [
      "js/background.js"
    ]
  },
  "browser_action": {
    "default_icon": {
      "24": "images/icon-24.png",
      "48": "images/icon-48.png",
      "96": "images/icon-96.png",
      "512": "images/icon-512.png"
    },
    "default_title": "Choose elements to blur"
  },
  "icons": {
    "24": "images/icon-24.png",
    "48": "images/icon-48.png"
  },
  "permissions": [
    "activeTab",
    "contextMenus",
    "storage",
    "https://api.gumroad.com/*"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "hi@blur.page",
      "strict_min_version": "55.0"
    }
  }
}