Observer widget

[subzero911]

Currently we have only Rx types.
But your package does not provide anything to rebuild state.
So the only way is to convert Rx variables to streams and to build it with StreamBuilder (looks awkward).
GetX (based on your package) has Obx widget which works like
Obx ( () => Text ( counter.value ) ),

Please add the widget named Observer with the same functionality out of the box, so we wouldn't need StreamController or third-party solutions.