When comparing Blueprint vs Flutter, the Slant community recommends Flutter for most people. In the question“What is the best CSS framework?” Flutter is ranked 16th while Blueprint is ranked 48th.
Ranked in these QuestionsQuestion Ranking
Pro Open source
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 A single codebase for iOS AND Android
The developer's goal is to allow people to make apps running at 120 FPS.
Con No preprocessor support
No support for Sass, Less, or Stylus.
Does not follow the responsive web development philosophy.
It was last updated in 2011.
Con Still in development
According to the website, Flutter is still in its early stages of development.
Con Based on Dart language
Dart is a Java like language, easy to learn and startup fast for millions of Java developers. BUT if you have to learn it ... it's a con.
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.