If you've taken advantage of the great sale on the Nook HD (ending today), or if you've had one for awhile and recently upgraded to add the Google Play Store, you might be wondering what apps to add. Here's my list of must-have apps, not available in the Nook App store. 1. Feedly With Google Reader going away this July, you'll need another way to keep track of your feeds. I've been using Feedly for awhile now, and it's an excellent Google Reader replacement. In some ways, I've grown to like it better. For example, I've found its integration with Pocket to...