What are some alternatives?
When comparing Ordering Stack and Flipdish, you can also consider the following products
SambaPOS - SambaPOS is an open source POS Software for Restaurants.
Sapaad - Sapaad is a powerful, user-friendly, cost-effective Cloud Point-Of-Sale (POS) designed exclusively for restaurants of all sizes.
Lightspeed POS - retail and restaurant point-of-sale, ecommerce, and omnichannel solution
Brigade POS - Brigade is a full service restaurant point of sale system.
TouchBistro - iPad based Point of Sale solution for restaurants
Lavu - iPad Point of Sale System