Examine source code of Main Focus

{
  "manifest_version": 2,
  "short_name": "Main Focus",
  "name": "Main Focus",
  "author": "Saurabh Kumar",
  "version": "1.0.3",
  "description": "Main Focus, Weather and Time.",
  "icons": {
    "32": "icon32.png",
    "48": "icon48.png",
    "128": "icon128.png"
  },
  "chrome_url_overrides": {
    "newtab": "index.html"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{72bc4a97-0684-4bb2-a738-7ef394d66769}"
    }
  }
}