Many may not be familiar with Dropbox.
Install
Dropbox (online backup and file sync) on your computer. As you accumulate your .apk files, place them in the appropriate Dropbox folder.
Install the
Dropbox app on your NOOKcolor. Now you can access these files anytime should you be away from your computer. You may have to uninstall and re-install an app, and don't have the .apk file on your device/storage card. No problem if you have WiFi access!
Or you can place documents, ebooks, and videos in the Dropbox folder on your computer for anytime access. Many people do this with their calibre library. It's great for videos because you can delete from the device what you watched and download fresh content on the fly.