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..
Use the Google translator API to generate text to speech audio.
Find A, AAAA, CNAME, MX, NS, TXT, SOA DNS records of a host.
Get the web-host of a given website.