Examine source code of Tick Tab Clock

{
  "name": "Tick Tab Clock",
  "short_name": "TickTabClock",
  "description": "Tick Tab Clock extension will help you keep track of the time while enjoying a soothing new tab design.",
  "manifest_version": 2,
  "version": "1.0.2",
  "permissions": [
    "storage",
    "*://ticktabclock.net/*"
  ],
  "chrome_url_overrides": {
    "newtab": "html/index.html"
  },
  "icons": {
    "16": "images/manifest-icons/16.png",
    "32": "images/manifest-icons/32.png",
    "64": "images/manifest-icons/64.png",
    "128": "images/manifest-icons/128.png"
  },
  "background": {
    "scripts": [
      "sw.js"
    ],
    "persistent": false
  },
  "web_accessible_resources": [
    "images/manifest-icons/16.png",
    "images/manifest-icons/32.png",
    "images/manifest-icons/64.png",
    "images/manifest-icons/128.png",
    "html/index.html"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{aab95773-7f68-49e9-b701-7560df5bfa4e}"
    }
  }
}