Now that the summer book frenzy is in full swing, anything that helps us read a little faster is welcome -- so we're glad that Amazon just pushed out a relevant update to its Kindle app for iOS. The new 3.8 release adds line spacing options, so readers can fit more (or less) on to a page without tweaking the font. Those whose eyes demand an extra-large font can now pick one, too. Amazon is also laying some early groundwork for back-to-school with a focus on notation. It's at last possible to make highlights that span multiple pages, and Print Replica Textbooks gain filters for bookmarks, highlights and notes. Whether you're trying to get a jump on classes or just want to cram in one more novel during vacation, you'll want to swing by the App Store for the upgrade.