Designing UI in Flutter for Android

Yes. You can try the Flutter UI Open-Source library. Try this GitHub repo for Flutter UI design https://github.com/ionicfirebaseapp/getflutter

Short answer, no.

But Flutter has something called Hot Reload, which allows you to see your chances within a second.

Flutter’s hot reload feature helps you quickly and easily experiment, build UIs, add features, and fix bugs. Hot reload works by injecting updated source code files into the running Dart Virtual Machine (VM). After the VM updates classes with the new versions of fields and functions, the Flutter framework automatically rebuilds the widget tree, allowing you to quickly view the effects of your changes.

There's also something called Flutter Studio.

It's not supported right now. Flutter Studio doesn't look stable and have bugs in it. So the only preferable way up till now is to use Hot Reload. If you want to debug layout related issues, you can do the following:

1. import this in the root file (e.g. main.dart)

import 'package:flutter/rendering.dart';

2. in your main() function, add these lines to enable layout debugging before runApp() method:

debugPaintSizeEnabled = true;

debugPaintBaselinesEnabled = true;

debugPaintPointersEnabled = true;