Amazon has launched three revisions for the Kindle electronic-book system, thereby expanding its business. However, concerns are rising over its fading identity due to the excessive promotion of the e-book system.

Last Sunday, it proclaimed the upgrading of a multimedia app for the Kindle application for Apple's iPhone, iPod Touch and iPad.

The application was launched last year. The recent move will enable the users to use audio and video files loaded in Kindle.

However, this feature is missing in other Kindle softwares, launched in the previous week, including the reader program for Android smartphones.

The free Kindle app for Android seeks the devices to have the capability of running on Google's operating system. It is a lot similar to Seattle retailer's older iPhone software as well the BlackBerry application, which it launched in February.

Kindle for Android depicts the books that the users purchase on the Kindle Store and maintains an account of the number of times the user changes reading from one Kindle device to another.

Amazon considers the sales worth $379, falling against $489, and appears dressed in dark-gray plastic, which enables it to conceal dust in a better way.