This has nothing to do with the fact that your application was built using Phonegap. Apple simply believes that your application does not provide enough functionality to warrant an entire native iOS app. For example, your application cannot simply be a marketing tool.
You need to take advantage of the features iOS provides and give the user some sort of functionality in order for Apple to consider your app to be useful.
I've found including something extra in the app that links into the native API . For example a push notification/ native tabs etc. Check out the phonegap plugins and see if anything extra you can add.
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.