You must take advantage of the iPad launch and the benefits you can gain from it. For this, you should definitely make your iPhone App compatible with iPad also. When the iPad goes on sale in the market, Apple will be creating a new section in iTunes that lists new iPad Apps or enhanced iPhone Apps that are compatible with iPad.
All iPad users who have already downloaded your free or paid App to their iPhone or iPod Touch will be able to download your iPhone App – only if you have updated your binary submission to the App store to make your iPhone App compatible with iPad. If you do not update and create the separate binaries, then you are potentially losing out. Using the new SDK you will be able to create a single binary which will install one version of your app when used on the iPhone or iPod Touch and a different binary when installed on an iPad.
Rotation Orientation Support –
Supporting rotation is a must on the iPad. This is because the iPad does not have a normal way in which it will be held unlike the iPhone, which is normally held vertically (portrait view). With the iPad the user can be comfortable with both the vertical or horizontal (landscape) orientation. This means that your iPad App has to support both orientations – that is, it must be able to rotate and appear properly in both views.
View Controller -
All iPhone Apps which currently use UINavigator to switch to another view showing details of something selected in a list, can now take advantage of the new detailed view controller. This functionality will now provide simultaneous viewing of the list and the detailed view – when in landscape orientation, or a full-screen viewing of the details view with the list available in a popover view – when in portrait orientation. All of the Apps will have to been rewritten to use these new features and users will expect them of your applications as well. You should use the UIKit functionality to build this into your App.
Popover Views –
Popover views are not supported in the iPhone, but can be used to create modal dialogs, modeless dialogs, and menus in the iPad. Hence, all Apps which use the master/detail view, will automatically convert the master list to a popover menu when the iPad is placed in the Landscape orientation. You can use this same popover technology to create menus, such as shown in Pages and modeless dialogs. An example would be the color picker shown in the Brushes App, or creating D-pad controls. These popover views can easily be closed by the user by tapping on any region outside the popover window boundary. Hence, while designing, make sure you leave some areas on the sides where the user can touch the screen to dismiss the popover window. Design cleverly to see where you can replace entire views with Popovers. This will greatly simplify your apps on the iPad and the speed and ease with which users can navigate quickly. Don note that since the iPhone and iPad Touch do not support Popovers, you will need to create and use a custom view for them – should you use Popovers in your iPad App.
Tabs can appear on the top or at the bottom of the screen on the iPad. This gives you the ability to provide more traditional tabs on the top of the UX rather than just at the bottom. You can thus also put tabs in the top of your Popover views.
TableView controls can now have multiple columns. Therefore, try to eliminate custom controls or provide an enhanced UX to your users.
More Finger Gestures -
The limited screen size of the iPhone and iPad resulted in limitations in the possible touch screen finger gestures. With the iPad and its bigger screen, a whole new set of gestures are possible. There is plenty of space for long-touch and also drag gestures and multi-finger controls ( the 3-finger twist gesture ). You can see Steve Jobs doing this in the Developer Keynote Speech.
Also, since the iPad screen is large, Apple has built in a functionality that supports multiple users touching different parts of the screen at the same time. For example 2 people can play a game of hockey-puck with each other. The iPad screen is hence large enough to allow different simultaneous gestures in different parts of the screen so that each user can have their own virtual control surface area.
If you create video content areas, you do not have to display the video across the entire screen, and you can restrict video to only a small portion or area of the screen. This functionality can be used to combine the user experience with multiple multimedia functionality.
The iPad supports mounting a shared file directory by connecting the iPad via USB to a PC or Mac. This means you can easily share data files between your devices if required by the App.
The iPad also supports wireless headsets and microphone, thus allowing total hands-free voice-driven control of Apps.
The iPad has an optional “video out cable” – that you can use to project the screen in full or part. This is fantastic for making presentations.
Using CoreGraphics, all Apps will now be able to generate PDF content. This will allow you to generate reports in PDF should you App require this.
Compass and Location -
The Compass and Location / GPS functionality is only available in the higher models of the iPad that support 3G. While developing you should make sure to check for compatibility so that you can enable or disable the feature, as appropriate.
Text Input and Keyboards –
Each text input field (using the TextView function), will support spell checking and auto-completion by default – just as in the iPhone. You can define if you want to auto-enable or disable this functionality.
You can also implement multiple custom virtual keyboard layouts within a single App, thereby displaying different types of custom keyboard inputs like Scientific keys, I.P. address keys etc. for TextView controls as needed.
Bluetooth connected keyboards are supported out-of-the-box. No need to configure anything. Many users will probably selectively connect third party keyboards to their iPad. Your App can be developed to support such alternate text-input capability.
Screen Size Disparity -
Avoid undesirable uneven image stretching of your App when users change the orientation of the iPad. The iPad is 1024 pixels in the tallest dimension and 768 pixels in the shortest dimension. These proportions are not the same as with the iPhone or iPod Touch – and differ slightly. At the tall end the screen is 2.13x the size of the iPhone or iPod Touch. At the short end the size is 2.4x the size of the iPhone or iPod Touch. Therefore, this slight disparity in proportions will cause your view to stretch unevenly if you display it in full screen on the iPad. You will therefore need to customize this view, if required for the iPad, in order to avoid any uneven full screen resizing.
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