Convert text to binary and the other way for any string input.
Convert text to hexadecimal and the other way for any string input.
Convert text to ascii and the other way for any string input.
Convert text to octal and the other way for any string input.
Get the gravatar.com globally recognized avatar for any email.
Find A, AAAA, CNAME, MX, NS, TXT, SOA DNS records of a host.
Get approximate IP details.
Crop images to a specific size.
Make sure your passwords are good enough.
Get all possible details about a domain name.