The free app synchronises bookmarks between the iPhone and the Kindle. It was but has only just been made available in the UK following the Kindle's launch to the British market.
Other features on the app include the ability to choose font sizes and the number of words per line when reading on the iPhone. Users will also be able to read books in full colour and sample opening chapters.
The Kindle has been available in the US since 2007 however its launch elsewhere was delayed by questions of how its 3G technology can be implemented in overseas markets.
In October, Amazon launched an international version of the Kindle, which works in more than 100 countries, including the UK. The cost to a UK buyer is £175 but this rises to £200 when including import duties.