Is there any plugin name 'subscribe via email'?

Hi,
I had surfed a site that has a cool plugin which with a submit button as “subscribe via email”. And also allow the web master to add content like this:
Did you enjoy this post? Get XXXX Dot Com updates via email…
Stay up to date with all of XXXX’s tips for XXXX online and blog posts by subscribing via email. Your email will be kept private and never shared with anyone.
Enter Your email Address:
I respect your privacy. You may unsubscribe at any time with just one click.

The web master add it at the end of contents.

Is there anyone know about this plugin? Please let me know.
Thanks!