I've been wondering the same thing. From searching the boards here, it would appear that the app should be more interactive, although I'm not sure what that means.
I don't know what the difference is either. I started buying the apps when they first came out for the NC and really enjoy them. I just bought another last night They are $9.99 each and I think they cover more then one issue but I'm not sure about that, how does that compare with buying the comic?
Also, they take up space in your "app partition". I now have to archive something if I want to buy more issues, while I can still download books all I want. Maybe the difference is the NC treats the comic like a book and the app like an app.
I AM CONSIDERING PURCHASING THE WALKING DEAD COMIC? WHAT IS THE DIFFERNCE BETWEEN THE APP AND THE NOOK COMIC?
As far as content, unless the app specifically says it has interactive content, there is no difference, assuming you are comparing the same editions. The Nook Comic is probably a graphic novel edition that compiles several issues. Read the description, but the comic apps usually contain multiple individual issues, not the graphic novel format.
The comic apps first came out when there were no good Nook Comic options. The Nook devices do not support comic apps like Comixology or Marvel, so some comic distributors, like Graphicly, put out single use apps that contain a set number of issues of a particular comic. You can not use these apps to read other comics. Incidentally, Graphicly no longer supports its general purpose tablet comic reader that was made for its own content.
Now a days, the only real reason to buy one of the comic apps is if there is no corresponding Nook Comic.