Last week I posted my Google Android ebook reader showdown and concluded that Aldiko and Kobo were my favorite two applications. Many of us Google Android owners have been waiting anxiously for the release of the Amazon Kindle application and you can find it now in the Android Market for free. Jason Perlow already posted a review of the app with an extensive image gallery so I won't repeat the same thing here and recommend you check it out. Since I previously wrote a full review of the Kobo application for Android, let's take a closer look at how they stack up.
I understand that support for an in-app store, dictionary, and more are coming to the Kindle app while the furthest read support in the Kobo reader is being improved.
Both apps are currently limited in that they do not allow you to read EPUB books, including from other ebook stores or public libraries, that could be transferred via USB or microSD card connection. To read non-DRM EPUB books you should look at the Aldiko application that I wrote about in my ebook reader showdown.