A few weeks after surprise news that Amazon.com, Inc. acquired the company that created the iPhone reader, Stanza, the online bookseller announced an upgrade in the Amazon Kindle for iPhone app.

The new features include: portrait and landscape mode, the ability to zoom in on images in books, alternate background and text colors, and screen-tap page turning. The announcement made no mention of the company's intentions for Stanza--the former top free Book app in the iPhone store. It is now ranked #3 in the category--behind Amazon's reader and the American Bookseller Association's indieBound iPhone app.

Here's more from the release: "The Amazon Kindle for iPhone app, the most popular book app which launched in March 2009 in Apple's App Store, allows customers access to more than 280,000 Kindle books wirelessly on their iPhones, the ability to access their entire library of previously purchased Kindle books stored on Amazon's servers."