Take an IP and try to look for the domain/host associated with it.
Find A, AAAA, CNAME, MX, NS, TXT, SOA DNS records of a host.
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.
Get approximate IP details.
Separate text back and forth by new lines, commas, dots...etc.
Minify your HTML by removing all the unnecessary characters.