Increment Decrement Number
This plugin allows to display a "+" or "-" button next to a numeric fields to increment and decrement the number in the field by 1.
In order to setup the Plugin, you would be required to specify the:
* Fields - Specify the form fields where the buttons to increment and decrement values should be displayed. The fields must belong to Single Line Text or Numeric Allocation question types.
Please note, that this plugin also works with question and answer identifiers, so you can use them instead of question and answer numbers in plugin parameters.