Dear Sebastian,
We are sorry to say that FoodBook only supports global attributes for a variable product, it does not support custom attributes.
Please check this article https://docs.woocommerce.com/document/variable-product/ to know steps by steps on how to create a variable product using global attributes.
Moreover, you could use the “Add Features” option https://prnt.sc/u1hic4 of FoodBook.
Furthermore, there is no mobile application available. However, our plugin is fully responsive on mobile devices. You could browse your website on mobile to manage orders.
Best Regards,
ThemeLooks Support Team