functions.php

// add this to your theme's functions.php

/*
 * Define a custom option type
 * this type will repeat some text inputs
 */

function repeat_text_option_type( $option_name, $option, $values ){

  $counter = 0;

	$output = '<div class="of-repeat-loop">';

	if( is_array( $values ) ) foreach ( (array)$values as $value ){

		$output .= '<div class="of-repeat-group">';
		$output .= '<input class="of-input" name="' . esc_attr( $option_name . '[' . $option['id'] . ']['.$counter.']' ) . '" type="text" value="' . esc_attr( $value ) . '" />';
		$output .= '<button class="dodelete button icon delete">'. __('Remove') .'</button>';

		$output .= '</div><!--.of-repeat-group-->';

		$counter++;
	}

	$output .= '<div class="of-repeat-group to-copy">';
	$output .= '<input class="of-input" data-rel="' . esc_attr( $option_name . '[' . $option['id'] . ']' ) . '" type="text" value="' . esc_attr( $option['std'] ) . '" />';
	$output .= '<button class="dodelete button icon delete">'. __('Remove') .'</button>';
	$output .= '</div><!--.of-repeat-group-->';


	$output .= '<button class="docopy button icon add">Add</button>';

	$output .= '</div><!--.of-repeat-loop-->';

	return $output;
}
add_filter( 'optionsframework_repeat_text', 'repeat_text_option_type', 10, 3 );


/*
 * Sanitize Repeat Fields
 */
function sanitize_repeat_field( $input, $option ){
	$output = array_map( 'sanitize_text_field', $input);
	return $output;
}
add_filter( 'of_sanitize_repeat_text', 'sanitize_repeat_field', 10, 2 );

/*
 * Custom repeating field scripts
 * Add and Delete buttons
 */
function of_repeat_script(){	?>

	<style>
		#optionsframework .to-copy {display: none;}

		#optionsframework .of-repeat-group {
			overflow: hidden;
			margin-bottom: 1.4em;
		}
		#optionsframework .of-repeat-group .of-input {
			width: 80%;
		}

		.of-repeat-group .dodelete {
			float: right;
		}
	</style>

	<script type="text/javascript">
	jQuery(function($){

		$(".docopy").on("click", function(e){

		  // the loop object
		  $loop = $(this).parent();

		  // the group to copy
		  $group = $loop.find('.to-copy').clone().insertBefore($(this)).removeClass('to-copy');

		  // the new input
		  $input = $group.find('input');

		  input_name = $input.attr('data-rel');
		  count = $loop.children('.of-repeat-group').not('.to-copy').length;

		  $input.attr('name', input_name + '[' + ( count - 1 ) + ']');


		});

		$(".of-repeat-group").on("click", ".dodelete", function(e){
		  $(this).parent().remove();
		});

	});

	</script>
<?php
}
add_action( 'optionsframework_custom_scripts', 'of_repeat_script' );

options.php

// add this to your $options array

$options[] = array(
		'name' => __('Repeating Text', 'options_framework_theme'),
		'desc' => __('A repeating text input field.', 'options_framework_theme'),
		'id' => 'example_repeat',
		'std' => 'Default',
		'type' => 'repeat_text');