Kobo Desktop is a free client application similar to iTunes, that offers ebooks for sale from its own database. You can browse and buy books from dozens of catalogues offered by the Kobo service sorted by genre, recent added, and top 50. They also offer a great collection of free ebooks from the classic literature.
Kobo comes with a minimal interface based on a Mac like design with a simple an clean menu on the left. From the menu you can view the content of your library and store, and your account info. Each ebook will be opened in a separate window which features its own menu. This menu is dynamic and can be hidden any time in order not to disturb your reading session. But in case you want to browse the book’s chapters, or view the book’s content, you can bring the command menu in front by a simple click. For the perfect reading experience you can choose the full-screen mode.