Late on Tuesday, Apple updated its iBooks iOS app with several new features, as well as including some stability and performance improvements.

iBooks 1.5 adds a Night theme that turns the background black and the text white to make reading in a dark room easier on the eyes--and less intrusive to anyone else who may be around you. You can still choose Normal (white background, black text) or Sepia (yellowish background, black text) options as well.

A new Full Screen option lets you get rid of the rounded corners, stacked pages, book jacket graphic, and other attempts to make reading in iBooks feel like reading a printed book.

iBooks 1.5 adds four new font choices--Athelas, Charter, Iowan, and Seravek--and removes three--Baskerville, Cochin, and Verdana--in the process.

Apple also mentions new classic covers for public domain books, and a redesigned annotation palette makes it easier to choose a color for your highlighted text.

iBooks 1.5 is a free download from the iTunes App Store.