在现有的iOS应用程序中添加核心数据功能有困难

First off, I'll make mention that I've seen lots of answers to this type of question on this site and others, but I can't seem to relate those solutions to my problem. I do apologize, however, if the answer I'm looking for already exists or turns out to be incredibly simple (although I'm definitely hoping that's the case).First off, I'll make mention that I've seen lot