Examine source code of Zoho Books Timer Plus

{
  "manifest_version": 2,
  "name": "Zoho Books Timer",
  "description": "Start a timer and log time for your projects in Zoho Books, anywhere on the web!",
  "version": "1.10",
  "default_locale": "en",
  "background": {
    "scripts": [
      "js/bground.js"
    ],
    "persistent": false
  },
  "content_security_policy": "script-src 'self'; object-src 'self';",
  "permissions": [
    "cookies",
    "storage",
    "contextMenus",
    "https://gadgets.zoho.com/",
    "https://gadgets.zoho.eu/",
    "https://gadgets.zoho.in/",
    "https://gadgets.zoho.com.au/",
    "https://gadgets.zoho.jp/",
    "https://gadgets.zoho.uk/",
    "https://gadgets.zohocloud.ca/",
    "https://gadgets.zoho.sa/",
    "https://gadgets.zoho.ae/",
    "https://www.zoho.com/billing/login/",
    "https://www.zoho.com/",
    "https://www.zoho.eu/",
    "https://www.zoho.in/",
    "https://www.zoho.com.au/",
    "https://www.zoho.jp/",
    "https://www.zoho.uk/",
    "https://www.zohocloud.ca/",
    "https://www.zoho.sa/",
    "https://www.zoho.ae/"
  ],
  "icons": {
    "16": "image/Books-16.png",
    "32": "image/Books-32.png",
    "128": "image/Books-128.png"
  },
  "commands": {
    "_execute_browser_action": {
      "suggested_key": {
        "windows": "Alt+Shift+B",
        "mac": "Alt+Shift+B",
        "chromeos": "Alt+Shift+B",
        "linux": "Alt+Shift+B"
      }
    }
  },
  "browser_action": {
    "default_icon": {
      "16": "image/Books-16.png",
      "32": "image/Books-32.png",
      "128": "image/Books-128.png"
    },
    "default_popup": "index.html"
  },
  "web_accessible_resources": [
    "js/mainmenu.js",
    "css/styles.css",
    "js/bootstrap.min.js",
    "image/Books-timer.png",
    "image/Books-128.png",
    "image/Books-32.png",
    "image/Books-16.png",
    "css/datepicker3.min.css",
    "css/bootstrap-datepicker.min.js"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{e87b4d8f-b81b-49e8-9b9f-125c7f1965df}"
    }
  }
}