Days after the film adaptation of Paper Towns hit theaters, John Green's 2008 novel hit #1 on Apple's iBooks bestseller list. E.L. James's Grey held firm at #2 for the week ended July 27, Paula Hawkins's The Girl on the Train also stayed put at #3, and Harper Lee's Go Set a Watchman, which was the top selling title the previous week, fell to #4.

Rank, Book Title by Author Name, ISBN, Publisher

1. Paper Towns by John Green - 9781101010938 - (Penguin Young Readers Group)
2. Grey by E L James - 9781101946350 - (Knopf Doubleday Publishing Group)
3. The Girl on the Train by Paula Hawkins - 9780698185395 - (Penguin Publishing Group)
4. Go Set a Watchman by Harper Lee - 9780062409874 - (Harper)
5. Code of Conduct by Brad Thor - 9781476717173 - (Atria/Emily Bestler Books)
6. Luckiest Girl Alive by Jessica Knoll - 9781476789651 - (Simon & Schuster)
7. The Rumor by Elin Hilderbrand - 9780316334501 - (Little, Brown and Company)
8. The English Spy by Daniel Silva - 9780062320155 - (Harper)
9. To Kill a Mockingbird by Harper Lee - 9780062368683 - (Harper)
10. The Martian by Andy Weir - 9780804139038 - (Crown/Archetype)
11. Liam's List by Haleigh Lovell - No ISBN Available - (Haleigh Lovell)
12. The Nightingale by Kristin Hannah - 9781466850606 - (St. Martin's Press)
13. The Good Girl by Mary Kubica - 9781460330197 - (Harlequin)
14. All the Light We Cannot See by Anthony Doerr - 9781476746609 - (Scribner)
15. Dark Places by Gillian Flynn - 9780307459923 - (Crown/Archetype)
16. Down the Rabbit Hole by Holly Madison - 9780062372123 - (Dey Street Books)
17. Naked Greed by Stuart Woods - 9781101664247 - (Penguin Publishing Group)
18. Fifty Shades Darker by E L James - 9781612130590 - (Knopf Doubleday Publishing Group)
19. Truth or Die by Howard Roughan & James Patterson - 9780316408738 - (Little, Brown and Company)
20. Nemesis by Catherine Coulter - 9780698164895 - (Penguin Publishing Group)