Examine source code of Page Notes Pro

{
  "name": "Page Notes",
  "version": "3.4.9",
  "manifest_version": 2,
  "description": "Take notes for web pages and access them with a single click whenever you visit those web pages again. (Syncs to Google Drive)",
  "background": {
    "scripts": [
      "background.js"
    ],
    "persistent": true
  },
  "options_page": "options.html",
  "browser_action": {
    "default_title": "Page Notes",
    "default_popup": "popup.html",
    "default_icon": {
      "16": "icons/icon_16.png",
      "19": "icons/icon_19.png",
      "48": "icons/icon_48.png",
      "128": "icons/icon_128.png"
    }
  },
  "icons": {
    "16": "icons/icon_16.png",
    "19": "icons/icon_19.png",
    "48": "icons/icon_48.png",
    "128": "icons/icon_128.png"
  },
  "permissions": [
    "alarms",
    "identity",
    "storage",
    "tabs",
    "https://www.googleapis.com/",
    "https://accounts.google.com/"
  ],
  "web_accessible_resources": [
    "popup.html",
    "options.html"
  ],
  "oauth2": {
    "client_id": "441023963490-8fj45hkekop8ountdg3k7697ss9c5spv.apps.googleusercontent.com",
    "scopes": [
      "https://www.googleapis.com/auth/drive.file"
    ]
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{40983c5e-6070-40b1-b036-65878df23e9d}"
    }
  }
}