Last week, Amazon updated the Kindle App for the iPhone and iPad to version 2.2. If you haven’t already updated, it is worth doing so.

The update includes a free dictionary with 250,000 entries that you can use within a book by tapping on a word in the story. It also includes an improved “search inside the book” tool.

There is also a function to search words from the book on Google or in Wikipedia. Digg founder Kevin Rose should be happy about this update. He made a video earlier this summer, saying that he’d like to be able to search words from a book in Wikipedia and Google.