These apps are optimized for the larger screens of tablets and have either just hit the Android Market, or will be released this summer
Nook for Android
Just released, the Barnes & Noble Nook for Android app gains optimization for the larger screen sizes of Honeycomb tablets, and brings B&N's popular selection of interactive periodicals to tablets, too. Previously, B&N's interactive magazines were available only on the company's Nook Color tablet. You can initiate shopping for books and buying single copies or subscribing to periodicals directly from within the app. B&N says it has the largest selection of digital periodicals around, with more than 140 top magazines and newspapers in its collection.