Plugin that links key words?

I’ve seen some WP sites where the have a little icon next to a word, with a link to a website. So perhaps it’s a title of a book, a movie name, or the mention of google – the output is the normal text and words which have links to websites are linked. Is this some plguin that does this automatically?

So if I make a post which says today on WordPress I searched using google instead of Amazon – it creates a link for Amazon, WordPress and Google with that dinky lil icon next to it.

Thanks in advance