The iPad has had a big impact on aviation. iPads are holding charts and other vital information for professional pilots eliminating thousands of printed pages that used to be pushed into heavy black flight bags.
Now, a pilot has written an app called the Aviation Pilot Duty and Performance Calculator to assist pilots operating under Part 135 (commuter and on-demand flight operations) that does a lot of the calculations that are laborious and time consuming. The app helps pilots compute things like Departure Gradients, Climb Performance, Approach Planning, keeping track of flight time and more.
Pilots operating under FAA part 91 (general aviation) and Part 121 (commercial pilots) will also find many of the features built into the app helpful.
The Aviation Pilot Duty and Performance Calculator is a reasonable US $4.99 and is a universal app that is optimized for the iPhone 5 and requires iOS 6.1 or later.
This app is not for the casual flyer, but if you make a living in the air it is an invaluable time saving tool.