(jquery) Blackout the entire screen and highlight a section of the page?

Question

As per screenshot below. I am pretty sure someone has done this before! =)

The circle is a bonus, would be very happy with a solution that allows highlighting of a g

Answer 1

5 years since the question was asked, but it may help people arriving from google

I've developed a plugin for this matter,

You can get it from: Hop on Github

Let me know your feedback.