Minify your HTML by removing all the unnecessary characters.
Minify your JS by removing all the unnecessary characters.
Get the gravatar.com globally recognized avatar for any email.
Extract email addresses from any kind of text content.
Check if the URL is cached or not by Google.
Check if the URL is banned and marked as safe/unsafe by Google.
Get approximate IP details.
Check for 301 & 302 redirects of a specific URL. It will check for up to 10 redirects.