Take an IP and try to look for the domain/host associated with it.
Free Tool to Check A, AAAA, CNAME, MX, NS, TXT, SOA DNS records of a host.
Get all possible details about an SSL certificate.
Get all possible details about a domain name.
Ping a website, server or port..
Extract email addresses from any kind of text content.
Convert text to ascii and the other way for any string input.
Check if the URL is cached or not by Google.
Separate text back and forth by new lines, commas, dots...etc.