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.
Ping a website, server or port..
Extract email addresses from any kind of text content.
Use the Google translator API to generate text to speech audio.
Check if the URL is cached or not by Google.
Convert normal text to old english font type.
Separate text back and forth by new lines, commas, dots...etc.