Pouch enables you to use your 37signals Backpack account on your iPhone and iPad, including your Pages, Reminders, Calendars, Journal, and Newsroom.
Pouch is hands-down the best way to use Backpack on your iPhone and iPad.
Find out more in the App Store.
Note: Though Pouch supports a large portion of Backpack's many features, it can't do everything Backpack can because of limitations of the Backpack API and iOS. If you use Backpack for a specific function that Pouch does not cover, or if you have any questions or feedback, please feel free to contact me.