By the way, I'm adopting https://code.google.com/p/j2objc/ ASAP -- yesterday, if it were possible. I was just contemplating writing my own C++/jni bridge but I'll take what already works, especially if it's being battle-tested by Google. :)

Edit: And with bugs like https://code.google.com/p/j2objc/issues/detail?id=224 I'm considering changing my mind. My Java code isn't that great either, and a few classes with JNI might go a long way compared to hacking together ObjC from Java code. The hard part that neither directly addresses is how to integrate Gradle-powered flavours and build types with Xcode/iOS targets and simple macro keywords. Sharing language files, string/config values and some assets... all seem project-specific at this point and not very well generalized.