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.
Make sure your passwords are good enough.
Check for 301 & 302 redirects of a specific URL. It will check for up to 10 redirects.
Get details of any file type, such as the mime type or last edit date.
Get all the HTTP headers that an URL returns for a typical GET request.
Easily convert bytes (B) to yottabytes (YB).