An app is a focused view that handles tasks that are too complex for a complication, tile, or notification. Apps on Wear OS are similar to a mobile app's main user interface. Use surfaces such as tiles, complications, and notifications to accomplish simple tasks, but link these surfaces into an app to carry out more complex tasks.
Review the following principles and use cases for a better understanding of apps.
UX principles
Design apps with the following principles in mind:
- Focus
- Focus apps on critical tasks to help people get things done within seconds to avoid ergonomic discomfort or arm fatigue
- Shallow and linear
- Avoid hierarchies deeper than two levels. Show navigation inline
- Scroll
- Views can scroll. This is a natural gesture for users to see more content on the watch
When to use an app
Use apps in the following situations:
- For additional info
- Focus apps on critical tasks to help people get things done within seconds to avoid ergonomic discomfort or arm fatigue.
- For richer interactions
- To provide richer interaction than a complication or Tile.
- For adjusting preferences
- To provide access to education and preferences.
![app-focus](https://developer.android.com/static/wear/images/app_1.png?authuser=0000)
![app-rich](https://developer.android.com/static/wear/images/app_3.png?authuser=0000)
![app-pref](https://developer.android.com/static/wear/images/app_2.png?authuser=0000)
Building an app
Wear OS supports two distinctive ways of building an app:
Compose for Wear OS is a modern declarative UI toolkit and is the recommended approach for building apps on Wear OS.
Compose-based UIs in most cases result in less code and accelerates the development process of Android apps as a whole. See Why Compose for more information on the general advantages of a declarative UI framework.
The Compose Material Catalog for Wear OS follows material styling, includes built in accessibility, and implements material theming, which allows you to customize the design for your brand. Compose for Wear OS offers more components than are available with Views, and is designed to help you create user experiences that conform to Wear OS design guidelines.
If you have an existing Wear OS app with a large view-based codebase, it's possible to gradually adopt Compose by using the Compose Interoperability APIs rather than having to rewrite the whole codebase.
Guides for creating apps with Compose
- Use Jetpack Compose on Wear OS
- Learn how to build with Compose for Wear OS.
- Create lists
- Learn how to create lists that are optimized for wearable devices.
- Navigating with Compose for Wear OS
- Learn more about building navigation in Compose.
- Compose performance on Wear OS
- Learn more about performance and testing your app performance.