Barnes & Noble Inc. added an application store and an email program to its Nook Color electronic-book reader, giving the device more of the capabilities and functionality of pricier tablet computers.

The bookseller hopes the software upgrade will make the Nook Color, which has a touchscreen and runs Google Inc.'s Android software, an alternative for consumers who want features like email and games like Rovio's "Angry Birds." Barnes & Noble is also adding the ability to play Adobe Systems Inc.'s Flash video on its Web browser....