Unlike these guys, we're working on software that makes the waiter more efficient. You download the phone app and scan the code that the waiter gives you. From there, you have shared list between you and all your friends at the table from which you can send orders directly to the waiter from the app. The customers can hail the waiter and we plan to add direct messaging as well in the future.
We've noticed that while some people enthusiastically love the system, its a 50/50 split between those who prefer paying from in our app and those that pay the waiter directly the old fashioned way.
We're currently in a few select high profile restaurants in London and hoping to expand soon.