Today at Mobile World Congress, Google introduced Flutter, their new cross platform mobile SDK. The new development tool will allow for developers to create native UI frameworks for both Android and iOS that are native to each platform.
The beauty of Flutter is that it comes packing its own rendering engine and framework which, in essence, bypasses the native UI frameworks in both platforms. This is not something new for developers, especially game developers who have used different rendering engines. This allows for significant performance increases (particularly on Android). When you compile the app with the available Android and iOS SDKs, you get the appropriate app & framework for the respective platform.