For developers who have been building for iPhone and iPod Touch, the unit represents a new form factor and extended UI for presenting their applications. The tablet’s larger screen moves beyond the limitations of the tiny iPhone screen, boosting such applications as electronic book-reading, in-the-field forms applications, and even games.
The new iPad UI supports menus, panes, and windows familiar to developers from their Windows and Mac OS X apps, so it appears that they can adapt their desktop apps’ UIs fairly readily to the iPad. A new iPhone SDK that supports the iPad will be available for downlaod today, Apple says.
Developer interest appears heavy. In a survey of 554 of its developers last week, mobile and desktop platform provider Appcelerator found that more than 90 percent were interested in developing at least one Apple tablet application in the coming year. (Appcelerator will support development of Apple tablet applications.)
But with that interest comes a key question: Can developers create apps that work for both the iPhone and the iPad, or must they fork their apps or even create fully separate ones?
For a variety of reasons, many developers expect to see iPad-specific applications come to market that aren’t intended for iPhone use.
The iPad form factor opens possibilities that don’t make sense on an iPhone
A big reason is the tablet’s larger display enables display of more information, which helps developers such as Bill Vlohos, president of InfoWallet, which makes an information organizer for Mac OS X, Windows, and Linux systems. But such a UI is “going to be difficult to do on the small screen of a phone,” he notes (Vlohos plans on porting the app to the iPhone nonetheless).
The large display and the additional UI controls in the iPad also open the door for apps that didn’t make sense either on a smartphone like the iPhone or on a traditional tablet PC running Windows and using a pen interface. For example, “I think there will be a huge amount of adoption in medical [applications, with] the ability for doctor or a nurse to bring X-rays and other kinds of diagnostics and stuff to the bedside,” says Christopher Allen, co-founder of the iPhoneWebDev developer community. Likewise, salesmen can show content and write up orders on the tablet more easily than on an iPhone, he says.
What about existing iPhone apps?
Allen expects most existing iPhone and iPod Touch applications will work fine unmodified on the iPad in some kind of window or other mechanism. But developers will likely want to tweak those applications and create iPad-specific versions to, for example, take advantage of higher resolution and perhaps the addition of more players on the tablet, he notes. Allen will be making that assessment for his current iPhone card game app. “That would require some special programming because it will be not just more content, but the content behaves differently,” he says.
Mark Johnson of Focused Apps, which offers a Facebook application for the iPhone, concurs that running an iPhone application as-is on the iPad may not be optimal. “The optimal user experience for a tablet device would probably be a little different” than what is now supported on an iPhone application, he says.
To address this issue, the iPad adds a “2X” icon to existing apps that scales them up to the larger screen size. Apple’s demos today suggest that the iPad automatically smoothes the graphics and video at the larger size, such as for games.
Of course, developers will invest in iPad-specific versions only if the device is a success and promises them more app sales. “The tablet might be fantastic, and certainly we’ll try it out to see if our software runs on it. But if they don’t sell a lot of units, I imagine we’ll stay focused on the iPhone and iPod Touch,” says Johnson.