- WatchKit gives developers the ability to start developing and extending their iPhone applications to the Apple Watch.
- WatchKit is a framework that contains everything you need to create an Apple Watch application.
- WatchKit is an integral part of the Apple Watch experience for third-party applications.
- It contains the classes for creating Apple Watch applications and it ensures that an Apple Watch application can talk to its corresponding WatchKit extension.
What is WatchKit App?
- A WatchKit app is a user launchable app that appears on the Apple Watch home screen.
- A WatchKit app is the user’s main way of viewing and interacting with your data.
- It provides the means to view your data and optionally to manipulate or interact with that data. Depending on the data, a WatchKit app might present only a subset of the data presented by its containing IOS app.
How it exactly works?
- A WatchKit app acts as the public face of your app but it works in tandem with your WatchKit extension, which is the brains of the operation.
- The WatchKit app contains only the storyboards and resource files associated with your app’s user interface.
- The WatchKit extension contains the code for managing content, responding to user interactions, and updating your user interface. And because the extension runs on the user’s iPhone, it can coordinate with your iOS app as needed to perform more sophisticated tasks.
What do we have access to with WatchKit?
- WatchKit apps have two parts: A WatchKit extension that runs on iPhone and a set of user interface resources that are installed on Apple Watch.
- When your app is launched on Apple Watch, the WatchKit extension on iPhone runs in the background to update the user interface and respond to user interactions.
- WatchKit provides three opportunities to extend your iPhone app to Apple Watch:
- Your app on Apple Watch contains a full user interface. Users can launch, control, and interact with your app in ways unique to Apple Watch.
- You can provide users with timely read-only information that they care about with a Glance a quick and lightweight view of your app.
- vThink news, weather, stocks, sports scores or other small, easily digestible information.
- ESPN has already been working on a Watch app that funnels scores and news to Glances. American Airlines will send gate changes or flight status updates to the wrist.
- Actionable notifications built and designed with WatchKit let users take action right from their wrists.
- Developers can create notifications that allow users to take action or respond right from their wrist such as turning the lights off after they’ve left the house, quickly accessing flight details at the airport, and rerouting their transit when a train or bus is late.
- Developers can incorporate Glances, which quickly show users information they care about most, such as the latest news and sports scores, alarm system status or the next step of a favorite recipe.
How do these WatchKit applications work?
- WatchKit apps require an iPhone to function. This means that when you design your WatchKit apps, the Storyboard files for the watch application are loaded onto the Apple Watch; however, the code used to update interface elements and perform tasks is run on the iPhone instead. This means that in order for your application to work, the user must be paired to their iPhone.
- This lack of native functionality may be enough to turn some developers off to the idea of developing a current generation WatchKit app.
- Apple Watch apps are built similar to extensions in iOS 8, allowing a developer of an existing iPhone application to include an extra WatchKit Target in their project.
- Once built and loaded onto a paired iPhone, the WatchKit application can be run on the Apple Watch, processing all code on the actual iPhone instead of the watch. I believe this could help battery life by offloading CPU-expensive tasks to the iPhone.
- WatchKit apps have a dozen UI components, compared to the myriad of built-in and custom UI components that you can have on iOS and OS X.
- Here are some of the components you can use to build Apple Watch applications:
- These controls are what you will use to build out applications in your Storyboard you don’t have to worry about AutoLayout, XIBs, or anything else.
- The WatchKit Storyboard will automatically layout your on-screen elements by flowing them one after the other.
- Group: A container that manages the layout of other items.
- Table: Displays one or more rows of data.
- Image: Displays a static or animated image.
- Separator: A line for separating content in your interface.
- Button: A tappable area with a title and/or image.
- Switch: A control for indicating a binary value.
- Slider: A control for selecting a floating-point value from a range of continuous discrete values.
- Label: Displays a static text string.
- Date: Displays the current date and time.
- Timer: Displays a string that counts up or down to a specified time.
- Map: Displays the user’s location or the location of specific place marks.
- Menu: Displays a list of menu items (used with Force Touch).
- Menu Item: Executes an action method of the parent interface controller (Menu).