NumberPicker 
NumberPicker is a custom widget designed for choosing an integer or decimal number by scrolling spinners.
Example:
(See example for more)
class _IntegerExample extends StatefulWidget {
@override
__IntegerExampleState createState() => __IntegerExampleState();
}
class __IntegerExampleState extends State<_IntegerExample> {
int _currentValue = 3;
@override
Widget build(BuildContext context) {
return Column(
children: <Widget>[
NumberPicker(
value: _currentValue,
minValue: 0,
maxValue: 100,
onChanged: (value) => setState(() => _currentValue = value),
),
Text('Current value: $_currentValue'),
],
);
}
}