You won’t find FBReaderJ in the Android Marketplace just yet, but after another fix or two, it should be submitted. The reader software has long been available for computers running Windows or Linux and also runs on several Linux-based phones. I’ve used FBReader on a Nokia Internet Tablet and it’s a solid application; my issue has always been one of of content as most of my eBook library is constrained by some DRM format. FBReader doesn’t work with any of those titles, but does support a large number of non-DRM content types: HTML, FB2, TXT, RTF, and ePUB to name a few. The Android version currently supports OEB, ePUB and FB2 for starters, with other formats to follow.
TeleRead says the FBReaderJ version for Android can be directly downloaded and installed to your Android handset if you’re feeling adventurous. The app is written in Java and the developers expect to build a version for J2ME devices, so there’s a ton of phones that could support it in the future.