Examine source code of Site Blocker

{
  "manifest_version": 2,
  "name": "Site Blocker",
  "description": "Track how much time you've wasted on the web",
  "version": "1.4resigned1",
  "author": "Allen-B1",
  "homepage_url": "https://goo.gl/5V7fpD",
  "permissions": [
    "tabs",
    "storage",
    "idle",
    "history",
    "contextMenus",
    "activeTab",
    "alarms"
  ],
  "options_ui": {
    "browser_style": true,
    "page": "settings/settings.html"
  },
  "browser_action": {
    "default_title": "Site Blocker",
    "default_popup": "popup/popup.html",
    "default_icon": "icons/ic_timer_black.svg"
  },
  "background": {
    "scripts": [
      "lib/blocked.js",
      "background.js"
    ]
  },
  "icons": {
    "48": "icons/icon_48.png",
    "96": "icons/icon_96.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{991047f4-7fee-4950-994d-a524e4ff449e}"
    }
  }
}