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 decimal and the other way for any string input.
Convert text to octal and the other way for any string input.
Extract email addresses from any kind of text content.
Get the gravatar.com globally recognized avatar for any email.
Make sure your passwords are good enough.
Get & verify the meta tags of any website.
Find A, AAAA, CNAME, MX, NS, TXT, SOA DNS records of a host.
Get details of any file type, such as the mime type or last edit date.