class _FooClassState extends State<FooClass> with SingleTickerProviderStateMixin {

  late AnimationController _animationController;
  late Animation<double> _animation;

  @override
  void initState()  {
    _animationController = AnimationController(vsync: this, duration: const Duration(milliseconds: 700));
    _animation = Tween<double>(begin: 0, end: 1).animate(CurvedAnimation(parent: _animationController, curve: Curves.easeInOutCirc));
    super.initState();
  }

  void _showIcon() {
    _animationController.forward();
  }
  
  ...

IconAnimated(
  color: Colors.green,
  progress: _animation,
  size: 100,
  iconType: IconType.check,
),

_showIcon()

/// If you want to do the reverse
/// do this
/// _animationController.reverse();