When talking about mobile applications, the concept of the software’s posture doesn’t come up often. Posture is essentially the program’s behavioral stance, or the way it presents itself to the user. Alan Cooper, in About Face 3.0, explains that desktop and Web applications can fit into four posture categories: sovereign, transient, daemonic, and auxiliary. You’ll have to buy the book if you want a thorough definition of all of these categories, but Cooper’s discussion of how posture applies to handheld devices mentioned that they are usually transient and that the sovereign category is still a developing area. I want to limit this discussion to those two categories and specifically, to when and how the sovereign posture might be used with mobile applications.
As applied to a program accessed on a desktop or laptop computer, sovereign means that the program is best used full-screen and is often kept up and running continuously — think email and word processors. Transient programs come and go, and are just opened when needed to perform a discrete task and then closed again.
For this post, I’m going to talk in my personal realm of experience with an iPhone 3GS and other smartphones I’ve spent time with. The posture definitions just provided need to be massaged a bit to apply them to mobile applications on smartphones. With a smartphone, one and only one application’s interface can be visible on the display. Therefore, an open application is always full-screen. Whether it can be kept up and running depends on whether the device platform you are using allows for multiple applications to run simultaneously. I’d like to propose a new definition of a sovereign posture for the mobile application because of a unique feature that at least one mobile applcation I’ve used has taken advantage of — the ability to override the device’s auto-lock setting and maintain primary display without any additional input.
I have an iPhone app called FluxTunes that really capitalized on a thorough understanding of the mobile device user’s context of use. The application basically provides an alternate interface to iTunes targeted toward the person on the move who doesn’t want to fiddle with small touch controls. Though settings can be modified, by default all you have to do is one-finger-tap to toggle between Play and Pause, and swipe left or right to move between songs. What’s cool is that the affordance for the finger tap is the entire screen, so it’s impossible to miss your target and very easy to control without looking at it.
There are several other features I won’t get into here, but the feature that relates to posture is the auto-lock override. Typically, when a smartphone “goes to sleep” after a defined period of time, the user has to take some sort of action before getting back to an open application (on iPhones, pressing the Home button and then swiping to unlock if you don’t have a passcode). That means two actions before getting to the application, which can be a signficant requirement in certain situations. However, when your device sleeps with FluxTunes on, it’s still sovereign. It still takes finger tap input directly, with no intervening action required. This is super-handy when driving or when exercising — say to pause to answer a child yelling from the backseat or to quickly skip to another song or playlist during a jog.
I’d like to see this posture used by some other applications I have. One that is particularly frustrating is the Bible iPhone app that I use. When I use it, I’m often listening to a sermon or discussing a topic with a small group and I want it to work more like a reference book, one that’s open and stays open even when I’m not touching it for a while. However, the posture of the application makes it as if the book closes every time I’m not reading it for a few minutes. I would bet that several study or reference-type applications would have a very similar context of use among their audience.
I’d like to see whether tablet applications are taking advantage of this feature, because this context of use would be even more likely for student or professional situations. Anyone have a tablet application that works this way? How about smartphone apps? I’d love to hear what’s out there.