When comparing Appcelerator Titanium vs Flutter, the Slant community recommends Flutter for most people. In the question“What are the best frameworks for developing cross-platform mobile apps?” Flutter is ranked 1st while Appcelerator Titanium is ranked 12th.
Specs
Ranked in these QuestionsQuestion Ranking
Pros
Pro Provides a native experience
Through using Titanium's API and UI components similar to that of the platform's native UI, Titanium provides a native experience.
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
Pro Fast
The developer's goal is to allow people to make apps running at 120 FPS.
Cons
Con Has specific requirements with regards to installed libraries
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.