Fish-Redux-Library package, by Alibaba

Fish-Redux-Source, project code

Flutter-Movie, A non-trivial example demonstrating how
to use Fish Redux, with more than 30 screens, graphql,
payment api, and media player.

BLoC / Rx

A family of stream/observable based patterns.

Architect your Flutter project using BLoC pattern,
by Sagar Suri

BloC Library, by Felix Angelov

Reactive Programming - Streams - BLoC - Practical Use Cases,
by Didier Boelens

GetIt

A service locator based state management approach that
doesn’t need a BuildContext.

GetIt package, the service locator.
It can also be used together with BloCs.

GetIt Mixin package, a mixin that completes
GetIt to a full state management solution.