Being an error only the app-store version makes me suspicious of a project or target setting used to build the submission binary.
It might be your animation block blocking the main transition running behind. Try to avoid these kind of situation. For example popAviewController and just after push another this kind of situation lead to crash because you are doing another transition before previous one finished.
Hope you understand.
I cant really gove you an answer,but what I can give you is a way to a solution, that is you have to find the anglde that you relate to or peaks your interest. A good paper is one that people get drawn into because it reaches them ln some way.As for me WW11 to me, I think of the holocaust and the effect it had on the survivors, their families and those who stood by and did nothing until it was too late.