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.
Upload a QR code image and extract the data out of it.
Convert normal text to old english font type.
Get all possible details about an SSL certificate.
Make sure your passwords are good enough.
Convert text to hexadecimal and the other way for any string input.