Barnes & Noble might be pushing the Nook as hard as it can, but the retailer has always said it wants to build a reading platform across devices, and it’s making a big step in that direction with the launch of its eReader for iPad app today. The app allows Nook users to download most of their content to the iPad — the books all work, but some periodicals like the New York Times and Wall Street Journal aren’t available yet — and there’s a nice bookshelf view with jacket art and a library search function, which the Kindle app and iBooks don’t have. As with the Nook and other B&N clients, the iPad client supports LendMe for certain titles, but there’s no in-app purchasing — selecting “add books” from the bookshelf view kicks you out to the browser, just like the Kindle app. We’re not sure if this is an Apple restriction or a design decision, but we were told B&N is looking into adding in-app purchasing in a future release.

As for reading, eReader is actually quite flexible — you can customize the page, text, highlight, and link colors any which way you want (we made some hideous combinations), and there are some nice presets themes as well, ranging from “The Printed Page” to an inverted setting called “Night Light.” You can also set books to display using the publisher’s settings, and there are the usual line spacing and justification options as well. The only issues we had were with page turns and rendering — flipping from portrait to landscape too fast would result in some brief wonkiness, and flipping pages too quickly would eventually stall the app and lead to a brief load time. Neither was a deal breaker, but there’s clearly some room for polish here — we’re sure B&N is planning to iterate this rapidly, so we’ll see what happens. All in all, though the eReader app is a worthy competitor for your iPad ebook dollar — as long as iBooks has the only in-app store it’ll remain our favorite iPad reader, but if you’ve already purchased Nook content this is a solid free addition to the ecosystem.