[hugh3]

a) Not everybody has a smartphone

b) Most people don't want to download another damn app just to be able to eat at your restaurant.

c) Being able to order before you arrive usually isn't really a big advantage -- otherwise places would have done it long ago by phone.

Might be useful for take-out food during the lunchtime rush, though -- order and pay for your lunch from the office, and then stroll down to collect it. But some places already have an web-based system for this, with no need for a separate app. Still, I guess the app-based idea might make life slightly easier -- just show the screen of your phone to pick up your order.