Examine source code of Naoshite

{
  "manifest_version": 2,
  "name": "Naoshite",
  "version": "2.1.2",
  "description": "スクリーンショット撮影ツール",
  "homepage_url": "https://www.naoshite.net/",
  "icons": {
    "16": "icons/16.png",
    "19": "icons/19.png",
    "32": "icons/32.png",
    "38": "icons/38.png",
    "48": "icons/48.png",
    "64": "icons/64.png",
    "128": "icons/128.png",
    "256": "icons/256.png",
    "512": "icons/512.png",
    "1024": "icons/1024.png"
  },
  "permissions": [
    "cookies",
    "activeTab",
    "storage",
    "contextMenus",
    "<all_urls>"
  ],
  "content_scripts": [
    {
      "matches": [
        "http://*/*",
        "https://*/*"
      ],
      "js": [
        "content.js"
      ],
      "css": []
    }
  ],
  "browser_action": {
    "default_popup": "popup.html"
  },
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "options_ui": {
    "page": "options.html",
    "open_in_tab": true
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{24d73d71-5d6c-4232-b220-e10cd9dfa6ee}"
    }
  }
}