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..
Generate an MD2 hash for any string input.
Convert text to octal and the other way for any string input.
Convert text to ascii and the other way for any string input.
Minify your HTML by removing all the unnecessary characters.