Yes...it's true. There is now an app for that. Recently, Smart introduced their long anticipated iPad app for Smart Notebook. The app is not meant to replace Notebook entirely but to supplement it's use in the classroom. Using this app, you can create and edit Notebook files as well as download from the Smart Exchange. Currently the cost of the app is $6.99 and it is only available for the iPad. For more information about the app check out the video demonstration created by James Hollis of Teachers Love Smartboards...
UPDATE: Check out the Smart Notebook app review by James Hollis which details the successes and shortcomings of the new app.
If you have a Smartboard in your classroom then you know all about Smart Notebook and how valuable it is when using the board. Although this app is not designed to take the place of the program (no access to the gallery and lesson activity toolkit) it is a great way to edit on the fly. Don't forget that you can also access the Smart Notebook Express website which will allow you to create and edit your Notebook files on a computer that does not have the Notebook software.