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..
Get the gravatar.com globally recognized avatar for any email.
Decode Base64 input to back to string.
Convert text to ascii and the other way for any string input.
Make sure your passwords are good enough.
Check for 301 & 302 redirects of a specific URL. It will check for up to 10 redirects.
Encode any string input to Base64.