In addition to ACF, you can now use Meta Box to create your custom fields.
Zion Builder v 3.1.0 changelog
Pro Version
Added: MetaBox integration for dynamic fields
Added: Ability to specify the post excerpt length for dynamic field
Added: WooCommerce cart totals element
Added: WooCommerce cart products element
Added: WooCommerce cart cross sells element
Added: WordPress conditionals as element display conditions
Added: WooCommerce customer total orders as element display condition
Added: WooCommerce customer total spent as element display condition
Added: WooCommerce cart as element display condition
Added: WooCommerce products from cart as element display condition
Added: WooCommerce cart total value as element display condition
Added: WooCommerce product info as element display condition
Added: Browser info as element display condition
Added: Cookie as element display condition
Added: URL variable as element display condition
Added: Operating system as element display condition
Added: Referrer as element display condition
Added: Function return value as element display condition
Added: User login status as the element display condition
Improvement: Removed jQuery dependency for slider builder element
Improvement: Allow custom breakpoint values to work for slider builder > slides to show
Free Version