Amazon has released a free e-book reader application for Apple's iPad, offering access to hundreds of thousands of books.
The company claimed that the Kindle for iPad application will complement the Kindle reader, offering synchronisation of books across a variety of Kindle apps, and a user interface tailored to the look and feel of the iPad.
"Kindle for iPad is the perfect companion for the millions of customers who already own a Kindle or Kindle DX, and a way for customers to download and enjoy books even if they don't yet have a Kindle," said Jay Marine, director of Amazon Kindle.
UK users get a choice of 375,000 books, including some uploaded by independent publishers on Amazon's self-service platform.
The company said that its Whispersynch technology for harmonising content could be used to create a consistent reading experience, such as bookmarks, across a range of devices.
Amazon does not release sales figures for the Kindle hardware, but does report strong revenues from the device in its financial results.
Analysts have suggested that the hardware is a loss leader, and that the real money is made from book sales, prices of which Amazon fought to control.
Some parts of Atacama have not received rainfall for 500 years - but a sudden deluge of water upset the Desert's delicate biological balance
Spitzer Space Telescope could not spot Oumuamua, suggesting that it is actually pretty small
Greenland crater one of the 25 largest impact craters on Earth
This long-sought progenitor star was identified in an image captured by Hubble in 2007