Michael, how the software works is that it probably has a setting that says -
Check SD Card for content.
When you had side-loaded the app - that setting got turned on.
Now, you have gotten the store app. However, that setting is still alive.
So when SD Card is loaded it tries to load from SD Card.
1) There might be a setting in the app to change where data is read from.
2) The other option is to find out what directory on SD Card data is saved. And create such a directory and move data from Nook to SD card.
3) While redownloaded will not 'double' space used, it might not help - What you really need is some way to turn off the flag that says - Data for this App is saved on SD Card.
You should contact the app developer. The product page (where you bought it for Nook) has email and phone information.
I had LDS Gospel Library on my Nook Color and really appreciated it. (downloaded and installed from Barnes & Nobel app store). This is the app I use most. I decided to give my Nook Color to my daughter and purchased a new Nook HD+ for me. I wanted to put my favorite apps on the new Nook HD+. Gospel library installs but fails to run - problems with "catalog" needs refreshed, but database is in use so it can never run even if it installs.
Since I find my old Nook Color apps on the new Nook HD+ I decided to uninstall LDS gospel library from the Nook Color and try to uninstall from both systems and start fresh.
It didn't work and worse now I find the LDS Gospel Library is no longer available in the Barnes & Noble app store so I can not run it on either Nook. (It is still in playgoogle for install on Nook HD+ - but I can not get it to run, other apps from playgoogle work fine).
Are others having any trouble? Is this a known issue?
You should contact those people (The App people) and ask them to make the Google Play one work on Nook HD and HD+.
It is a known issue. I wrote them last week and this is what they said:
Barnes and Noble's recent update for the Nook HD and HD+ has caused problems with the Gospel Library app and we are working on a fix. We are in the process of testing the update with the fix in it and will try to make it available as quickly as possible. Please check the Google Play store regularly for the update. When it is available, you will have the option to update the app instead of just Open or Uninstall. We appreciate your patience as we work on a solution to the problem.