I have been using OmniGraffle on my Mac for years. It is, in my opinion, the premiere diagraming application on the Mac. I do some of my best thinking when I sit down and organize my thoughts visually with a diagram. The ability to quickly put together professional looking diagrams is a definite edge in my day job. I have even had other attorneys ask me what company I used for my “graphics” when in fact it is just me and a few minutes with OmniGraffle.

OmniGraffle on the iPad is not a simple port of the existing Mac application. The Omni team started from scratch. The user interface was re-designed from the ground up around the touch interface and the iPad’s screen size. Interestingly, the developers did not have access to an actual iPad when developing this application. Instead, they used a fiberglass cut out in bits and pieces of paper with user interface elements printed on it to figure out how to put the application together. Regardless, the programmers overcame this handicap and released an outstanding product.

There are many features worthy of exploration in iPad OmniGraffle. The first time you open iPad OmniGraffle, you are presented with a series of documents that show you the ropes. You should go through the built-in tutorial. There is a lot under the hood with this application and you can save yourself a lot of time down the road if you learn the basics first.

There is no menubar but instead a series of smart icons that are context sensitive. For instance, hitting the pencil icon brings up icons which are a pre-formatted square and free hand drawing tool. Once you create your object, you can move, resize, shadow, and color it just as if you were on your Mac. It is remarkable how quickly the gestures built into OmniGraffle becomes second nature. You can even attach objects with magnetic lines that remain attached as you move them around the screen. While none of this is revolutionary in comparison to the native Mac OS X application, it is remarkable that this can be created so easily without a keyboard a mouse. It almost feels like playing the piano.

That being said, a few times the interface was more complex than it needed to be. Setting object order, for instance takes some doing from the layers menu. I would prefer a simple “Send to Back” button.

I found the physical process of creating and moving these boxes with my fingers even more intuitive than doing it in front of the keyboard. The Omni group also included smart guides which allow you to snap your objects in alignment with one another. Even better, you can set up a grid with custom spacing and snap your objects to the grid as you create them. With very little time you can have a precise looking diagram and, with the touch of a button, remove the grid.

iPad OmniGraffle ships with a nice assortment of images, connectors, shapes, software tools, and variables. If you have any favorite stencils on your Mac, you can copy them over to your iPad and OmniGraffle will import them.

iPad OmniGraffle allows you to assign your objects to layers and turn them off and on as the need arises. I have already found it useful when sharing data with clients. Building a diagram in small pieces and then adding the layers one at a time makes it much easier for the audience to digest complex data.

iPad OmniGraffle is an outstanding implementation of the touch interface. Any aspiring iPad developers should take a long look at the care and deliberation that went into this application. Since the iPad released, the Omni Group has already made a significant upgrade fine tuning the user interface now that they have got their hands on an iPad.

At $50, OmniGraffle certainly is more expensive than most applications you will find in the iPad store but it is a professional graphics application. The OmniGroup has gone on record to explain that if you buy OmniGraffle and are unsatisfied, they will provide a refund. OmniGraffle, in any iteration, is not necessary for everyone. But if you find yourself using it on the Mac, pick it up for your iPad.

This review is based on an evaluation copy of OmniGraffle provided by the Omni Group.