The EPO has long had the best API for patent data/process access. I you want a free Flutter widget (or app) to build on use the contact form on the site.
Great set of refs and links … although a few seem for Android than DART.
Flutter is out of Beta … so we have Flutter 1.0 using Dart 2.1 as its default programming language. Here is a collection of articles on the release. The best: Everything That Google Announced About the Flutter 1.0 Others: Flutter 1.0 Is Now Available: Stable
Another web page collection with good basic examples.
Some more good articles on flutter development.
Hundreds of Flutter ready packages ready to jump start some complex functionality. Check it out at: https://pub.dartlang.org/packages
Great set of front screens and descriptions to show what is possible using flutter. Of course you need to load it on your phone to experience their functionality. Click here: https://itsallwidgets.com/
A very nice and recent article (June 2018) with some great visuals that really de-tangle some of the relationships between state, context and widgets. Nice code samples as well. Looks like the beginning of a nice book on the subject.
Working with the navigation example at Flutter.io I felt there must be a better way to work this issue … and a little searching found this article:
Came across a nice article: http://bizz84.github.io/2018/03/18/How-Fast-Is-Flutter.html discussing Flutter performance (its a few months old) vs a similar timing app in iOS. It’s main takeaways are (confirming suspicions): Frequent UI redraws are expensive If you call setState() often, make sure that it redraws as little UI as possible.