I did a search and tried to track down any other posts that may have dealt with this as well, so I apologize if I missed something and am re-posting about a covered issue.
I have a Nook HD and have always been very happy with it, and my 3-year-old daughter loves the Disney Read-Along books that read to her and tell her when to turn pages, etc.
I recently installed the Nook for PC app, thinking that I could use that as another medium for going through the Read-Along books if the Nook is being otherwise used. However, it appears the app doesn't support any of the books in that format (audio packaged with the book). I assume the same will be true once I try to access them through the Nook for Android app as well, since neither is listed as supported on the B&N website page for the various Read-Along books.
For the record, it is clear on the website what devices support these ebooks, so I don't feel Barnes and Noble has done anything wrong or misrepresented information. It would just be nice if support for this type of file/ebook could possibly be integrated into the various app types.
Unfortunately, your assumption about those books not being available on the Android app is correct. Quite a few magazines fall into this category, also. B&N needs to make the reading experience more consistent across their apps.