Make sure your passwords are good enough.
Get & verify the meta tags of any website.
Take an IP and try to look for the domain/host associated with it.
Find A, AAAA, CNAME, MX, NS, TXT, SOA DNS records of a host.
Compress and optimize images for a smaller image size but still high quality.
Get all possible details about an SSL certificate.
Generate passwords with custom length and custom settings.