A:
If this is a Simple Touch or variant (E-Ink screen)...there are no app options.
Either upgrade to the nook HD or HD+, or you could consider rooting it (I've never done so, that's basically hacking the OS, and that just flat out scares the capers out of me)...but the power is lacking in the E-Ink variants to make it worthwhile.
Simple Touch, Simple Touch with Glowlight & Glowlight are just simply Readers. Not Tablets or even Tablet-wanna-bes.