Apple ruffled quite a few feathers when it changed the rules for app publishers with in-app purchasing enabled. App developers had to make a decision if their business would support Apple's royalties on products purchased on the iPhone/iPad through apps. The ebook sector reacted understandably about these new rules as prices do not allow any room for Apple's royalties on sales. Amazon took matters in its own hands and just days after altering the Kindle app on iOS to remove access to Amazon's store, it released the Kindle Cloud Reader for the iPad to bypass Apple's conditions for apps. The Kindle Cloud Reader is based on HTML5 and as a web-based solution it is not subject to Apple's rules as they apply to apps.
The new reader seems to be a solid alternative to the iOS Kindle app that is still available, according to colleagues Matt Miller and Adrian Kingsley-Hughes. Amazon has created a compelling alternative to the native Kindle app that integrates seamlessly with Amazon's Kindle bookstore.
Android enthusiasts are already complaining that Amazon has ignored its own platform with the Cloud Reader by only offering desktop and iPad versions. It sounds like an error on Amazon's part but the fact is no Android (nor webOS) version is needed. Both Android and webOS have good Kindle apps that are nicely integrated with the Kindle bookstore, and believe me that is the only purpose behind the Cloud Reader. Amazon may eventually replace all of these mobile Kindle apps with the universal HTML5 version to keep support and development simple, but for now these mobile apps already exist and work just fine.
Many iPad owners will probably keep using the "restricted" Kindle app without direct access to the Kindle bookstore. The Cloud Reader is just another thing to keep track of for them and since it's not in the App Store they may choose to ignore it. If that's the case then Amazon hasn't accomplished much with introducing this clever end-around Apple's rules for apps.