Amazon today posted a major update to the Kindle app for the iPad and iPhone (free, App Store). Its 2.5 update now takes advantage of iOS 4 and will finish, though not start, a book download in the background. Borrowing from its companion app Stanza, it now supports raw files as well and can load supported text from Mail or Safari in addition to using iTunes' File Sharing for sideloading books from a computer.
