Just when you thought Apple's iron-gated app garden was sure to keep any challenger to iBooks out, along comes Amazon Kindle for iPad. Sporting a nifty book cover browsing interface, this upcoming app — assuming it makes it past Apple's stinky, troll-like gatekeepers — will let users read Kindle-formatted books on their iPads, offering customizable background colors and font sizes to ease eye strain, in-app screen brightness adjustment, the ability to sync bookmarks and reading place with Kindles and other Kindle apps, and the requisite "page turn animation" that replicates the look of actually turning a page in a book. You know, a real one — made out of paper? Never mind.