Examine source code of DTB - Daily Tool Box

{
  "manifest_version": 2,
  "name": "DTB - Daily Tool Box",
  "short_name": "DTB",
  "version": "2.0.0",
  "description": "Your Daily Tool Box. A new tab full of developer tools — Base64, Timestamp, Hash, JSON, JWT and more — plus a clock and your IP.",
  "permissions": [
    "tabs"
  ],
  "chrome_url_overrides": {
    "newtab": "newtab.html"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "randomfeed@pixelstech.net",
      "strict_min_version": "109.0"
    }
  },
  "browser_action": {
    "default_popup": "popup.html",
    "default_icon": {
      "16": "icons/icon16.png",
      "32": "icons/icon32.png",
      "48": "icons/icon48.png",
      "128": "icons/icon128.png"
    }
  },
  "icons": {
    "16": "icons/icon16.png",
    "32": "icons/icon32.png",
    "48": "icons/icon48.png",
    "128": "icons/icon128.png"
  }
}