Examine source code of Simply New Tab

{
  "manifest_version": 2,
  "name": "__MSG_extensionName__",
  "version": "1.1.1",
  "description": "__MSG_extensionDescription__",
  "default_locale": "en",
  "permissions": [
    "tabs",
    "browserSettings"
  ],
  "chrome_url_overrides": {
    "newtab": "newtab.html"
  },
  "background": {
    "scripts": [
      "background.js"
    ],
    "persistent": false
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{6494a36d-798a-4612-95be-68c3a207cdfa}"
    }
  }
}