Code

/**
 * Show custom fields in post content area
 *
 * @global object $post
 * @param string $content
 * @return string
 */
function wpuf_show_custom_fields( $content ) {
    global $post;

    $show_custom = wpuf_get_option( 'cf_show_front', 'wpuf_general' );

    if ( $show_custom != 'on' ) {
        return $content;
    }

    $form_id = get_post_meta( $post->ID, '_wpuf_form_id', true );

    if ( !$form_id ) {
        return $content;
    }

    $html = '<ul class="wpuf_customs">';

    $form_vars = get_post_meta( $form_id, 'wpuf_form', true );
    $meta = array();

    if ( $form_vars ) {
        foreach ($form_vars as $attr) {
            if ( isset( $attr['is_meta'] ) && $attr['is_meta'] == 'yes' ) {
                $meta[] = $attr;
            }
        }

        if ( !$meta ) {
            return $content;
        }

        foreach ($meta as $attr) {
            $field_value = get_post_meta( $post->ID, $attr['name'] );

            if ( $attr['input_type'] == 'hidden' ) {
                continue;
            }

            if ( $attr['input_type'] == 'image_upload' || $attr['input_type'] == 'file_upload' ) {
                $image_html = '<li><label>' . $attr['label'] . ':</label> ';

                if ( $field_value ) {
                    foreach ($field_value as $attachment_id) {

                        if ( $attr['input_type'] == 'image_upload' ) {
                            $thumb = wp_get_attachment_image( $attachment_id, 'thumbnail' );
                        } else {
                            $thumb = get_post_field( 'post_title', $attachment_id );
                        }

                        $full_size = wp_get_attachment_url( $attachment_id );
                        $image_html .= sprintf( '<a href="%s">%s</a> ', $full_size, $thumb );
                    }
                }

                $html .= $image_html . '</li>';

            } elseif ( $attr['input_type'] == 'map' ) {
                ob_start();
                wpuf_shortcode_map_post($attr['name'], $post->ID);
                $html .= ob_get_clean();
            } else {

                $value = get_post_meta( $post->ID, $attr['name'] );
                $html .= sprintf( '<li><label>%s</label>: %s</li>', $attr['label'], make_clickable( implode( ', ', $value ) ) );
            }
        }
    }

    $html .= '</ul>';

    return $content . $html;
}