Working with our hands...

While nearly everyone who first uses an iOS device has had an experience with a traditional button based cell phone, the large screen touch based devices offer a significant difference by allowing a truly orientation independent device.

In many respects, the decision to create a device which functions as properly right side up as it does upside down was intentional on Apple's part. All iOS devices contain a single, circular, and orientation neutral button that sends the user back to the home screen upon impression. All other menus and buttons to control an application are produced on screen and as such, defined by the developer.

This establishes an incredible sense of free reign for creative design in application perspective. Games such as Doodle Jump by Lima Sky can offer entertaining and fast paced play mechanics while various Twitter applications can offer landscape views for reading or typing away at tweets. Applications such as Ocarina by Smule can flip an iPhone or iPod touch completely on its head and require a user to rotate the device completely around so that the microphone can be used to mimic an actual ocarina.

In deciding which orientation best fits our iPhone or iPod touch application, the general purpose of our app will help guide our way. In nearly every situation, the user expects the application to function properly within the portrait orientation. Unless our app is a game that requires a simulated control pad and buttons or landscape orientation, we should always assume that users will expect portrait orientation in some respect or another. Landscape can offer an intriguing and greatly appreciated bonus for many users, especially in applications that depend heavily on typing or data entry, as many users prefer typing on the larger landscape keyboard.

While the above flexibility applies to smaller iOS devices, Apple demands orientation independence when working with the iPad. Unless there is a specific reason as to why an iPad app could not support both landscape and portrait view, we're expected to design our application to fit both perspectives.

Designing visually appealing work for both portrait and landscape perspectives on the iPad can be a challenging experience. The device features a 4:3 aspect ratio which creates a screen size that's not quite a square, but not wide enough to be a true widescreen perspective either. This provides an interesting problem where it is difficult to create two unique orientation interfaces that work well in their own way.

To help account for both orientations, Apple has developed a fair amount of new interface elements for our use in an application. Popovers and Dual pane views are just two new tools that are at our disposal to help produce quality interfaces. Tab Bar and Navigation Bar views have also been redeveloped to help better fit the larger screen as well. In designing our application, we should provide some sort of dual interface perspective that best works to provide clear navigation regardless of orientation.

Instapaper by Marco Arment implements a prime example of an iPad application that provides a dual pane interface when in landscape view and a single pane presentation aided by a Popover sheet when in portrait view.

When holding an iPhone in portrait view, the thumb of the hand holding device is easily available for use on screen. This portrait view also allows for the opposite hand to also be used as a way to interact with the device with ease. When holding an iPhone in landscape view, the device is typically held in a fashion that allows for only the thumb of each hand to be used to interact with the screen. As such, the landscape perspective is best used for typing or game applications.

Due to the large size of the iPad, the device offers a different experience with regards to holding and interacting with the screen. Typically, the iPad is held with two hands much like a book, with one hand lifting up to touch on screen with the pointer finger when input is needed. A large bezel surrounding the device prevents a finger from accidentally coming in contact with screen and makes it difficult for a thumb to move from a relaxed position to the screen. This distance makes applications or games with persistent interaction, such as a game with a software simulated control stick, difficult to play for extended periods of time because the hand will naturally fatigue while being held up to touch the screen.

With this information in mind, we should be able to develop applications that behave predictably for the user. When the user knows what to expect with our app, time spent learning the application will diminish and users will have more time to enjoy our work.

Screen sizes and the touch surface can vary based on the device, which means we shouldn't assume a great iPhone app will automatically make a successful iPad app.

It all depends on how you hold it

While the iPad and iPhone both run iOS, the size difference between the two devices can cause us to hold each considerably different. The iPhone and iPod touch are primarily one-hand devices while the iPad is more commonly held with two hands like a book.

Just because an interface works well on an iPhone doesn't mean it will necessarily translate to the bigger device and vice versa. Likewise, actions that work well with in one way on iPhone may need a different gesture or a button on iPad.

These size differences help demonstrate why we should have multiple test devices on hand during development. Just because one mechanic works well on a specific device doesn't mean we should assume that it would work well on another.