Take an IP and try to look for the domain/host associated with it.
Get approximate IP details.
Get all possible details about an SSL certificate.
Get all possible details about a domain name.
Ping a website, server or port..
Check if the URL is cached or not by Google.
Convert text to hexadecimal and the other way for any string input.
Find A, AAAA, CNAME, MX, NS, TXT, SOA DNS records of a host.