Well, you've got the main idea correctly. :)

You can look at screenshots here:
http://dl.dropbox.com/u/407819/MacBookReader/MBR1.png
http://dl.dropbox.com/u/407819/MacBookReader/MBR2.png
http://dl.dropbox.com/u/407819/MacBookReader/MBR3.png
http://dl.dropbox.com/u/407819/MacBookReader/MBR4.png

In case anyone is wondering, I tried to make sense of the Google translation of the homepage, here's what I think I have gathered -

This reads FB2 format ebooks. I personally have never encountered this format before, which also means I've never seen a reader for it. So if you have ebooks in this format, you may very well need this!

It appears to be written in Java. There are no screenshots, but I wouldn't expect it to be pretty. On the upside, there is also a Windows version and a Linux version. On the downside, it seems the author would love to make an iPhone version, but can't because of the reliance on Java.

Finally, the program is open source in a sense - it seems that if you just email the author and ask for it, he'll get you the source code.