Revel VS Lavu POS // Arduino pos printer library

I just typed this answer up for another question, so I'm going to copy and paste it into here, since it's applicable. These two systems are best for small establishments—quick serve or full service with a minimal amount of tables, coffee shops, and the like:* Instore, designed specifically for small quick serve establishments, would translate nicely into a smallish table serve setting. Apart from keeping open tabs, it has a load of features that make ordering from your menu easy. I like the way it handles modifiers for dishes, with the ability to define common ones in advance (along with variable pricing) and custom modifications at the time order. And if you're the type of place that offers different daily specials, it has tight integration with Facebook, Twitter, and Foursquare, which will allow you to update your menu and broadcast the daily item to your followers/fans all from the same interface.

* Change, which is similar to Instore in many regards, but has the ability to create entirely new items on the fly, right from the app. This is especially helpful in a bar setting, where it's impossible to create a menu of every cocktail that exists in advance. It's pretty easy to add a mixed drink to your line-up right at the time of order, so you don't have to worry when someone comes in orders an obscure drink last enjoyed by Zelda Fitzgerald in 1927. Also, Change is the first (and I believe still the only) POS to accept payments from Dwolla, integrated right into the interface, which represents a major cost savings over credit transactions.

Both of these are iPad based apps, with data syncing to the Cloud in real time. This gets you all the neat-o features cloud-based software comes with, like never having to back up your stuff or fix a server, and real-time analytics accessible from anywhere. Because the apps are run locally, though, it means you don't lose functionality if the internet goes down. They continue to run smoothly during an outage, though you won't be able to handle credit card payments if you've integrated that in to the POS.

If you find that you need a little more oomph to your POS—maybe the table layout is important, or you want ingredient level tracking—I'd recommend checking out POS Lavu or Revel Systems. Both are more expensive, both in up front and recurring payments, but you do get what you pay for with them and are well worth investigating.