...
The spinner widget is an input widget used for numeric input. Users can change the value using the up/down arrows, or users can set the value by typing it.
Validation (Rich UI Only)
...
If you bind the value property to a program value, then the data should be integer type:
For more information about binding, please visit the Field Binding page. Binding is available for the Rich UI only.
...
max value - Sets the maximum value for the spinner widget. (Found under Field Settings.)
increment value - Specifies how much the widget is increased or decreased when the up-arrow or down-arrow is clicked. By default, increment value is '1'. (Found under Field Settings.)
...