Amazon bought LexCycle which created the first widely used ebook reader for the iPhone (Stanza – a free app)…
Lexcycle has been acquired by Amazon.com! (announcement)
Amazon Acquires Stanza, an E-Book Application for the iPhone (New York Times)
Amazon itself released the Kindle iPhone ebook reader in March (also free). And, as you can see from the iTunes App Store top free ebook apps list above, Kindle for iPhone and Stanza are the two most popular free iPhone ebook apps. The Wattpad ebook reader is #3 and Fictionwise’s eReader (FYI: Barnes & Noble owns Fictionwise) is #4.