A repeater field add-on allows you to repeatedly add a set of form fields within your WordPress forms. It will enable users to click an Add button to add another group of fields. This add-on is very useful if you want users to add details about multiple items in a form and required number of form fields items are not pre-defined. It makes the form short and helps in conversion.
Example: If you have to create a form where visitors are asked to enter family member details. Then it is not predefined how many family members the visitors have and varies depending upon the person. So pre-populating fields might not be a viable solution. In such a case, repeater fields come in handy, and visitors can add new fields as per the requirement. The user can add family member details simply by clicking add new member, and a set of fields will be repeated.