Library for highlighting important parts of page [on hold]

I have used ShowcaseView in Android and it's very good for pointing the user in the right direction on a complicated page aka a tutorial. An example can be seen below.

What I'm wondering is, is there anything similar to this for web pages to help guide the user and explain various parts of the page? It doesn't have to be the same as ShowcaseView as long as it will help get the point across.

I tried lots of Googling but trying to Google anything with the word tutorial returns the wrong things!