Amazon sent out a press release earlier today announcing that they will be bringing Kindle to the Android platform. Hitting SD card-equipped Android 1.6+ handsets this summer, the free app will allow users to read, browse and purchase from within the app. It will also include Amazon’s Whispersync technology that keeps your books and progress consistent no matter where you read your Kindle books.
This all sounds like standard Kindle functionality, and it is, but the ability to browse, buy and read books without leaving the application is something that isn't possible in the iPhone and iPad versions. TechCrunch mentions, if Amazon was to sell books within the app itself, they would have to kick 30% to Apple for in-app purchase requirements, so it makes sense why that functionality isn't there, but it's still inconvenient.
In a market that is quickly moving towards the commoditization of ebook readers, Amazon continues to focus on getting their marketplace on as many devices as possible. This is the Microsoft Window's approach that has proven to be successful in the past, and just may leave Apple's iBooks in a similar situation to the minority stake OS X holds today.
Kindle software is currently available for almost all major platforms, including: PC, Mac, iPhone, iPad and Blackberry.