I have found an I phone and an I pad app called Audiobooks, by cross forward consulting. This app is free and offers 3,500 free audio books. Some authors of interest that Audiobooks offers for free would be, Ayn Rand, Friedrich Nietzsche, George Bernard Shaw, Herbert Spencer, Jules Verne, Niccolo Machiavelli, Sigmund Freud and many more. This app is easy to use and has some nice features.

Enjoy as I have,

Hail Satan!
The question is not "Who will let me?" but rather "who will stop me?" - Ayn Rand