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 approximate IP details.
Get all possible details about an SSL certificate.
Get all possible details about a domain name.
Check if the URL is cached or not by Google.
Separate text back and forth by new lines, commas, dots...etc.
Minify your HTML by removing all the unnecessary characters.