Available in three sizes and prices ($34.99 for 8 gigabytes, $49.99 for 16 GB, and $89.99 for 32 GB), the SD card plugs directly into the Nook, letting the device boot into Android mode. A boot menu gives users the choice of loading Android or the Nook operating system, while removing the card will automatically transform the Nook back into its normal e-reader state.
In Android mode, Nook owners can use the built-in Wi-Fi 802.11 a/b/g/n to surf the Web and run various preinstalled apps, such as Gmail, Facebook, and Pandora, according to Nook2Android. Apps can be downloaded and installed directly from the Android Market. The company also promises that using the cards won't affect the Nook's internal memory or void the warranty from B&N.