Apple released the first beta of its iOS 8.2 software development kit (SDK) to registered Apple developers last week, and it includes the initial release of WatchKit, the SDK component that developers will use to make Apple Watch apps. A quick look at its contents makes clear that the first generation of third-party apps for Apple Watch will be remote display and input extensions to iPhone apps. There’s nothing wrong with that, of course, but if you were hoping to see a flurry of rich, immersive Apple Watch apps pouring into the App Store from developers early next year, it’s time to reset your expectations.
The WatchKit framework, the part of the SDK that provides the software interfaces that developers use for building Apple Watch apps, consists of little more than a list of the user interface objects that appear on the watch: menus, buttons, sliders, labels, tables, and the like. Missing are interfaces for, say, playing sounds or displaying videos, or for accessing the watch’s hardware features.
As the Apple Watch Human Interface Guidelines (included in the SDK) make abundantly clear, Apple Watch apps are lightweight, intended to complement iOS apps rather than replace them. The model looks something like this: an iOS app uses a WatchKit-enabled extension running in the background on an iOS device to exchange data with a paired Apple Watch in order to display information and elicit simple input from the watch’s wearer. For example, a restaurant guide running on an iPhone could send listings for nearby restaurants to the watch, and the user could page through them to pick where to eat. However, given the Apple Watch’s limited screen space (a paltry 340 by 272 pixels on the 38 mm Apple Watch screen, and a slightly more expansive 390 by 312 pixels on the 42 mm model), such information would have to be pared down to a bare minimum — roughly about the same amount of content than you could send in a single tweet on Twitter.
Apple describes two basic types of user interaction with Apple Watch, and both are seen as being brief interactions, lasting just a few seconds, not complex engagements taking minutes: Glances and Notifications. Both of these types are displayed only when the watch wearer lifts the watch to look at it.
A Glance fits on a single screen and displays information from an iOS app. If the wearer taps the screen, the action opens the app on the linked iOS device that sent the information. More than one iOS app can be running at a time, periodically sending information to the watch, and wearers can swipe up to scan through the current set of Glances.
A Notification alerts the wearer via the Taptic Engine interface provided by Apple Watch — that is, you feel a tapping on your wrist. When the wearer raises the watch, the “short look” version of the notification appears, displaying just its bare essentials (for example, that a meeting is about to begin). A tap on the notification, or keeping the wrist raised, reveals its “long look” which can contain more information (for example, the meeting is about to begin in 7 minutes in conference room C) as well as up to four buttons for responding to the notification. Long look notifications must be dismissed explicitly by the wearer.
WatchKit also provides Modal Sheets, much like modal dialogs on a Mac or iOS device. These take over the Apple Watch interface until the user dismisses them and are used for short tasks that require one or more steps. Modal Sheets have a close button to close or cancel the sheet.
And that’s pretty much the range of interactions that a third-party Apple Watch app can offer. At least for now. In its press release, Apple did say that “Starting later next year, developers will be able to create fully native apps for Apple Watch.” So we can expect more fully featured third-party Apple Watch apps to start appearing eventually. Just not now.
And that’s OK. It’s better that Apple takes things slowly, as the company did with the original iPhone, rather than committing to decisions that might be regretted later.