DigitalTop 20 Free Book Apps of the WeekBy Dianna Dilworth|September 8, 2011 ShareBy Dianna Dilworth|September 8, 2011 Share iBooks was the most popular free app in the Apple App Store this week, according to research from AppData, Inside Network’s data service that tracks app and developer leaderboards.Explore these 20 free apps and find out what kind of literary apps succeed in this crowded marketplace. To prepare for Mediabistro’s upcoming Publishing App Expo on December 7-8, we spotlight the top grossing book apps, the top paid Android books apps and the most popular free apps every week.Below, we’ve listed the top free iOS apps of the week–linking to App Data’s research about each individual app, including historical charts, developer information and download details.20 Top Free Apps (Books Genre)September 8, 20111. iBooks2. Kindle3. NOOK for iPhone from Barnes & Noble-Read 2 Million Books, Free Books4. Audible5. Comics6. The Little Red Riding Hood HD – So Ouat!7. Audiobooks8. 1 million FREE Books – Read Kobo eBooks!9. Weird Facts 100010. B&N Bookstore11. Unlimited Free Books – Wattpad eBook Reader12. Google Books13. OverDrive Media Console – Library eBooks and Audiobooks14. Bible+15. Love Quotes 50016. Sex-Facts 50017. å˜å½¢é‡‘刚3å‰ä¼ -å¥ åŸºæ—¶ä»£18. Marvel Comics19. 100+ Horror Stories20. iScroll Adweek Adweek