Just days ahead of the debut of the film adaptation of If I Stay, Gayle Forman’s novel was once again the top seller in Apple’s iBooks store. Lois Lowry’s The Giver, which opened in theaters last week, came in at #2 for the week ended August 18, and Liane Moriarty’s Big Little Lies hit #3.

As students prepare to head back to school, Joseph S. Levine & Kenneth R. Miller’s Biology came in at #6, and World History, by Roget B. Beck and others, landed at #9.

1. If I Stay by Gayle Forman - 9781101046340 - (Penguin Group US)
2. The Giver by Lois Lowry - 9780547345901 - (Houghton Mifflin Harcourt)
3. Big Little Lies by Liane Moriarty - 9780698138636 - (Penguin Group US)
4. Outlander by Diana Gabaldon - 9780440335160 - (Random House Publishing Group)
5. Fifty Shades of Grey by E L James - 9781612130293 - (Knopf Doubleday Publishing Group)
6. Biology by Ph.D., Ph.D., Joseph S. Levine & Kenneth R. Miller - 9780133226713 - (Pearson Education, Inc.)
7. The 6th Extinction by James Rollins - 9780062194923 - (William Morrow)
8. The Fault in Our Stars by John Green - 9781101569184 - (Penguin Group US)
9. World History by Dahia Ibo Shabaka, Larry S. Kreiger, Linda Black, Phillip C. Naylor & Roger B. Beck - 9780544025387 - (Houghton Mifflin Harcourt)
10. Insurgent by Veronica Roth - 9780062114457 - (Katherine Tegen Books)
11. Where She Went by Gayle Forman - 9781101476321 - (Penguin Group US)
12. Fifty Shades Darker by E L James - 9781612130590 - (Knopf Doubleday Publishing Group)
13. Divergent by Veronica Roth - 9780062077011 - (Katherine Tegen Books)
14. Gone Girl by Gillian Flynn - 9780307588388 - (Crown Publishing Group)
15. Fifty Shades Freed by E L James - 9781612130613 - (Knopf Doubleday Publishing Group)
16. The Heist by Daniel Silva - 9780062320070 - (Harper)
17. The Best of Me by Nicholas Sparks - 9781455502547 - (Grand Central Publishing)
18. Allegiant by Veronica Roth - 9780062209276 - (Katherine Tegen Books)
18. The Goldfinch by Donna Tartt - 9780316248679 - (Little, Brown and Company)
20. The Lost Island by Douglas Preston & Lincoln Child - 9781455525782 - (Grand Central Publishing)