I read about Flutter from Google today. Below are some snippets and the link.
As a cross-platform SDK, Flutter apps work on iOS and Android. It does a neat trick of kind of sidestepping both OS' UI frameworks.
Cross-platform development does not mean Flutter apps will feel out of place on your Android or iOS device. Flutter apps ship with built-in UI widgets for "Material Design" (Android) and "Cupertino" (iOS), which totally change how an app looks and feels. Flutter will change the scrolling behavior, buttons, sliders, dialog boxes, loading spinners, switches, tab bars, and more. If you want it to, a Flutter app really can feel just like a native app on both platforms. Shipping your own widgets also leads to a consistent look across Android's fragmented device ecosystem.
Shipping a whole engine along with every app does balloon the install size somewhat. The Flutter FAQ says an "empty" app is usually around 6.7MB on Android, so you're adding that much extra to whatever your app is. The benefit of doing this is that the Flutter is fast. Flutter is designed from the ground up to hit 60FPS, and, while this might not be a rare thing on iOS, you can immediately feel the difference in Android. You also get to sidestep a lot of Android's fragmentation issues, since you ship a platform along with your app.
Why I feel it is interesting ? Well, I most likely, will develop in Android and only dream of iOS as I do not have means for it. Flutter is helping me here with iOS development, as per the article above.
Now can we have B4A to develop in Flutter code, in coming future ? I Wish.
B4X is better, one language and you can program Software, Apps and Websites. And here is a great community if you have questions, on Google, I think less that it works as well as here.