theThe world of crossplatformcross-platform is a bitchpain. theThe most convientconvenient way is to create your game using openglesOpenglES, and then try to do specific ports to other devices.
withWith android you have to pretty much hack to get it going but it might be worth it. evenEven if the ndkNDK gives you the abbilityability to use c++, it still is Realyreally hard to get it going with a simple crossplatformcross-platform engine.
For android you have to use NDK, and for iOS you can compile c++ with objective-C.
So finalyfinally, it all comes down how you want to do it. eitherEither you do it realy realyreally easy and rewritesrewrite your game to javaJava, c++C++ and objectiveObjective-c ( might be awefullyawfully slow, but it´s easier than the rest). Or if you want to go with c++C++ on all devices and do special libraryslibraries for every devices and so on.