Minify your CSS by removing all the unnecessary characters.
Minify your JS by removing all the unnecessary characters.
Extract email addresses from any kind of text content.
Get approximate IP details.
Ping a website, server or port..
Find A, AAAA, CNAME, MX, NS, TXT, SOA DNS records of a host.
Get all possible details about an SSL certificate.
Take an IP and try to look for the domain/host associated with it.