App size increased when ported to IOS

My app size has more than doubled from 21MB to 44MB when ported over from android to ios and compiled in xcode (default settings with a few imported frameworks for admob and chartboost). Any ideas on why this is and if there is any way to reduce it?

I've gone through my texture settings after converting the project, and all of them seem to be the same, so im not sure on the sudden increase.