books if you know you won't finish it. good types of apps for these are the Kindle apps or if you have a new version of an iProduct, iBooks.
Like a paper-and-ink book, an electronic book is yours to keep once you've paid for it. The only downside to this is that, unlike paper books, you cannot pawn them off because the book is installed in your device.
Remember that electronic editions are more difficult than regular books to bring with you on long vacations or camping trips.