splash.dart

// Import the splash.dart into your main app and use like:
// ex: Splash(iconData:Icons.restaurant, label: 'MY APP',);


import 'package:flutter/material.dart';

class Splash extends StatefulWidget {
  final IconData iconData;
  final String label;

  Splash({Key key, @required this.iconData, this.label}) : super(key: key);

  @override
  _SplashState createState() => _SplashState();
}

class _SplashState extends State<Splash> with SingleTickerProviderStateMixin {
  Animation growAnimation;
  AnimationController animationController;

  @override
  void initState() {
    super.initState();
    animationController = AnimationController(
      vsync: this,
      duration: Duration(milliseconds: 800),
    );
    growAnimation = Tween(begin: 0.0, end: 1.0).animate(animationController);
    animationController.forward();
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      body: Container(
          child: _LogoAnimation(
        icon: widget.iconData,
        label: widget.label,
        animation: growAnimation,
      )),
    );
  }

  @override
  void dispose() {
    // TODO: implement dispose
    animationController.dispose();
    super.dispose();
  }
}

class _LogoAnimation extends AnimatedWidget {
  final IconData icon;
  final String label;
  _LogoAnimation({Key key, Animation animation, this.icon, this.label})
      : super(key: key, listenable: animation);

  @override
  Widget build(BuildContext context) {
    Animation animation = listenable;
    var fColor = Theme.of(context).cardColor;
    var bColor = Theme.of(context).primaryColor;
    return Scaffold(
      backgroundColor: bColor,
      body: Opacity(
        child: Stack(
          fit: StackFit.expand,
          children: <Widget>[
            // Progress layer
            Center(
              child: Container(
                height: animation.value * 180.0,
                width: animation.value * 180.0,
                child: CircularProgressIndicator(
                  strokeWidth: animation.value * 10.0,
                  valueColor: AlwaysStoppedAnimation<Color>(fColor),
                ),
              ),
            ),

            // Icon Layer
            Center(
              child: Container(
                width: animation.value * 150.0,
                height: animation.value * 150.0,
                child: icon == null
                    ? FlutterLogo()
                    : CircleAvatar(
                        child: Icon(
                          icon,
                          size: animation.value * 90.0,
                        ),
                        backgroundColor: fColor,
                      ),
              ),
            ),

            // App name layer

            Padding(
              padding: EdgeInsets.only(top: animation.value * 300),
              child: Center(
                  child: Text(
                label ?? '',
                textAlign: TextAlign.center,
                style: TextStyle(
                    fontSize: animation.value * 24.0,
                    color: fColor,
                    fontWeight: FontWeight.bold),
              )),
            )
          ],
        ),
        opacity: animation.value,
      ),
    );
  }
}