Most game engines are built as C/C++ and wrapped with Objective-C, Java, etc wrappers. It is really easy with games because you just need an OpenGL context and

Most game engines are built as C/C++ and wrapped with Objective-C, Java, etc wrappers. It is really easy with games because you just need an OpenGL context and some basic views, everything else can happen in the render. When you have to add native UI and integrate with libs like StoreKit, GameCenter, audio etc those are also wrapped. Still the best underlying tech is C/C++ for games. Even top engines like Unity export to this format. It would be entirely limiting to build an entire engine in Objective-C or Java for mobile multiplatform. C/C++ can be used everywhere with a little bit of wrapping.