Examine source code of New Tab Todo

{
  "manifest_version": 2,
  "name": "Todo New Tab",
  "version": "1.0",
  "description": "A simple todo app that replaces the new tab page. You can add your tasks for the day and mark them as completed.",
  "chrome_url_overrides": {
    "newtab": "index.html"
  },
  "permissions": [
    "storage"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "todo-new-tab@example.com"
    }
  }
}