Ranked in these QuestionsQuestion Ranking
Intel's App Framework is built to be lightweight and fast.
Pro Supports variety of platforms
Intel's App Framework allows you to build apps for just about any platform. iOS, Android, Windows 8, Tizen, Amazon, Nook, Chrome & Firefox.
Pro Great developer tools debug/hotreload/analyser
Pro Based on Dart language
Dart is a Java like language, easy to learn and startup fast for millions of Java developers.
Pro Open source
Pro A single codebase for iOS AND Android
The developer's goal is to allow people to make apps running at 120 FPS.
Con Weak documentation
The documentation for the app framework is fairly basic, with a limited number of descriptions/explanations given.
Con Still in development
According to the website, Flutter is still in its early stages of development.
Con Dart is unpopular and never gained serious community traction like Kotlin or Java
Con Does not support 32-bit iOS devices
If you plan on targeting iPhone 5, 5C or earlier, you can forget about Flutter.