iOS 6 compatibility
The Sept. 3, 2015 update to the Digital Publishing Suite (DPS) iOS viewer supports iOS 7.0 and greater, and is not compatible with iOS 6. The minimum supported phone and tablet devices on iOS 7 are the iPhone 4 and iPad 2, respectively (the iPhone 3GS is no longer supported because it cannot be updated to iOS 7). For details, see the iOS 6 Compatibility FAQ.
Receipt handling changes
This update includes changes to receipt handling in the iOS viewer. The viewer now supports the most recent receipt formats from Apple. Older receipt formats will no longer be retrieved by the latest version of iOS viewer. Existing iOS apps created with earlier versions of DPS will continue to work. In addition, end-users with existing folio and subscription purchases will be unaffected by this change and will continue to get access to their purchases.
However, if you use the JS API to validate receipts directly with Apple in a custom HTML storefront, you need to update your code to handle the new receipt format. For details on the JS API changes see Library and Store v2 SDK.