Global DNS allows you to instantly check the DNS records across multiple servers. It provides an insight to end users on which server website is pointing to.

Dominion is a WordPress plugin which allow you to swiftly check domain name availability from your WordPress site.

WP Domain Checker is a WordPress plugin that allows you to easily check the availability of a domain name from your WordPress site.

Age Checker is an age verification plugin for WordPress. This plugin asks users to verify their age on page load.

WHOIS Lookup is a full featured PHP script that can search for WHOIS information on any website.

The WooCommerce Pincode / Zipcode Checker module is a very necessary feature to check product availability by zip / pin / zip code.