Tag Archives: watch faces

Build kids app experiences for Wear OS

Posted by John Zoeller – Developer Relations Engineer, and Caroline Vander Wilt – Group Product Manager

New Wear OS features enable ‘standalone’ watches for kids, unlocking new possibilities for Wear OS app developers

In collaboration with Samsung, Wear OS is introducing Galaxy Watch for Kids, a new kids experience enabling kids to explore while staying connected with their families from their smartwatch, no phone necessary. This launch unlocks new opportunities for Wear OS developers to reach younger audiences.

Galaxy Watch for Kids is rolling out to Galaxy Watch7 LTE models , with features including:

    • No phone ownership required: This experience enables the watch and its associated apps to operate on a fully standalone basis using LTE, and when available, Wifi connectivity. This includes calling, texting, games, and more.
    • Selection of kid-friendly apps: From gaming to health, kids can browse and request installs of Teacher Approved apps and watch faces onGoogle Play. In addition to approving and blocking apps, parents can also monitor app usage from Google Family Link.
    • Stay in touch with parent-managed contacts: Parents can ensure safer communications by limiting text and calling to approved contacts.
    • Location sharing: Offers peace of mind with location sharing and geofencing notifications when kids leave or arrive at designated areas.
    • School time: Limits watch functionality during scheduled hours of the day, so kids can focus while in school or studying.

Building kids experiences with standalone functionality enables you to reach both standalone and tethered watches for kids. Apps like Math Tango have already created great Wear OS experiences for kids. Check out the video below to learn how they built a rich and engaging Wear OS app.

Our new kids-focused design and content principles and developer guidance are also available today. Check out some of the highlights in the next section.

New principles and guidelines for development

We've created new design principles and guidelines to help developers take advantage of this opportunity to build and improve apps and watch faces for kids.

Design principle: Active and fun

Build engaging healthy experiences for children by including activity-based features.

A great example of this is the Odd Squad Time Unit app from PBS KIDS that encourages children to get up and be physically active. By using the on-device sensors and power-efficient platform APIs, the app is able to provide a fun experience all day and still maintain battery life of the watch from wakeup to bed time.

A circular timer display with a hexagonal background 'JUMP!' and '5 SECONDS REMAIN'. A gold hand points to the number 5. A colorful segmented ring surrounds the center of the timer.

Note that while experiences should be catered to kids, they must also follow the Wear OS quality requirements related to the visual experience of your app, especially when crafting touch targets and font sizes.

Content principle: Thoughtfully crafted

Consider adjusting your content to make it not only appropriate, but also consumable and intuitive for younger kids (including those as young as 6). This includes both audio and visual app components.

Tinkercast’s Two Whats?! And a Wow! app uses age-appropriate vocabulary and fun characters to aid in their teaching. It’s a great example of how a developer should account for reading comprehension.

A smartwatch face displays a cartoon bird with a speech bubble that says 'SWIPE TO VIEW YOUR OPTIONS!'. Yellow arrows point left and right with a large letter 'A' between them.

Development guidelines

New Wear OS kids apps must adhere to the Wear OS app quality guidelines, the guidelines for standalone apps, and the new Kids development guide.


Minimize impact on device battery

Minimize events that affect battery life over the course of one session. Kids use watches that provide important safety features for their parents or guardians, which depend on the device having enough battery life. Below are best practices for reducing battery impact.

      ✅ DO design for offline use cases so that kids can play without incurring network-related battery costs

      ✅ DO minimize tasks that require an internet or GPS connection

      🚫 DO NOT use direct sensor tracking as this will significantly reduce the battery life

      🚫 DO NOT include long-running animations


Choose a development environment

To develop kid-friendly apps and games you can use Compose for Wear OS, our recommended approach for building UI for Wear OS, as well as Unity for Android.

We recommend Unity for developing games on Wear OS if you’re familiar and comfortable with its workflows and capabilities. However, for games with only a few animations, Compose Animation should be sufficient and is better supported within the Android environment.

Be sure to consider that some Wear OS quality requirements may require custom Unity implementations, such as support for Rotary Input.

Originator’s MathTango showcases the flexibility and richness of developing with Unity:

A purple cartoon moose-like character with large antlers is displayed on a round smartwatch face. The name 'ISAAC' is shown below the character, along with the label 'NEW!'. A green arrow is visible in the top left corner of the screen.

Creating Watch Faces

Developing watch faces for kids requires the use of Watch Face Format. Watch faces should adhere to our content and design principles mentioned above, as well as our quality standards, including our ambient mode requirement.

The following examples demonstrate our Content Principle: Appealing. The content is relevant, engaging, and fun for kids, sparking their interest and imagination.

The Crayola Pets Watch Face comes with a great variety of customization options, and demonstrates an informative and pleasant watch face:

A circular watch face shows a cartoon character, the time (3:30), the date (Feb 10), and a battery indicator (89%).

The Marvel Watch Faces (Captain America shown) provide a fun and useful step tracking feature:

A round smartwatch face displays a cartoon Captain America, his shield, and the time (12:30). A step counter shows 650 steps. The Marvel logo is visible.

Kids experience publishing requirements

Developers looking to get started on a new kids experience will need to keep a few things in mind when publishing on the Play Store.

Expand your reach with Wear OS

Get ready to reach a new generation of Wear OS users! We've created all-new guidelines to help you build engaging experiences for kids. Here’s a quick recap:

With the Wear for Kids experience, developers can reach an entirely new audience of users and be part of the next generation of learning and enrichment on Wear OS.

Check out all of the new experiences on the Play Store!

Latest updates for watch faces on Wear OS

Posted by Anna Bernbaum – Product Manager, and Garan Jenkin – Developer Relations Engineer

At last year’s Google I/O, we launched the Watch Face Format for Wear OS. This year, as part of our continued partnership with Samsung, we are excited to share some new features that you can use to create exciting new watch face designs! These features are now supported in XML definitions, and later in the year, you’ll also see an update to Watch Face Studio to take advantage of them.

The Watch Face Format is the recommended way to create watch faces for Wear OS. The format makes it easier to create customizable and more power-efficient watch faces for devices that run Wear OS 4 or higher. The Watch Face Format is a declarative XML format, so there is no executable code involved in creating a watch face, and there is no code embedded in your watch face APK.

Additionally, in our move toward the Watch Face Format for watch face creation, we have also made some changes to watch face development.

New features in the Watch Face Format

Flavors

Flavors represent preset configurations for your watch face, available in the companion app:

Watch gallery

They allow the watch face developer to configure useful and attractive combinations of the watch face’s configuration options, and allow the user to visualize and select from these with ease.

We’ve now brought flavors to the Watch Face Format. For a full guide on adding them to your watch face, see the flavors reference.

Complications

We’re adding support for both “goal progress” and “weighted elements” complication types to the Watch Face Format:

circle chart with data saying 60% of goal progress and weight elements circle chart

    • Goal progress is perfect for data where the user has a target, but that target can be exceeded. A good example is step count.
    • Weighted elements can represent discrete subsets of data, showing their relative sizes, where you might otherwise use something like a pie chart.

Both of these complication types can be accessed through the [COMPLICATION.*] expression object. For full details, see the complication guidance.

Weather

Knowing at-a-glance what the weather will be like for the next hour, day, and beyond can make all the difference to a user’s plans! Unsurprisingly, having weather data as a data source in the Watch Face Format has been a common request, and we’re delighted to be able to introduce it in this latest version. You’ll now be able make watch faces like this:

circle chart with data saying 60% of goal progress and weight elements circle chart

Weather Basics

Weather in the Watch Face Format is accessed via the [WEATHER.*] expression object. You can use it in Condition and text Template statements and anywhere where expressions are supported.

For example, to show the current weather condition, use this template and expression:

<Template>Current weather conditions: %s
    <Parameter expression="[WEATHER.CONDITION_NAME]"/>
</Template>

The weather provider in the Watch Face Format supports a range of different metric types for the current day, including the following:

    • Current conditions
    • Temperature - current, minimum (low), and maximum (high)
    • UV index
    • Chance of rain

For the full range of data types and conditions, see the weather guide.

Forecasts

In addition to the current weather, you can access forecast data, both by hour and by day. For example, to access the forecast maximum temperature for tomorrow, use a template and set of expressions similar to the following:

<Template>Tomorrow max temp: %d°%s
    <Parameter expression="[WEATHER.DAYS.1.TEMPERATURE_HIGH]" />
    <Parameter expression="[WEATHER.TEMPERATURE_UNIT] == 1 ? &quot;C&quot; : &quot;F&quot;" />
</Template>

When using weather in the Watch Face Format, there are some further details to be aware of, such as checking for forecast availability or loading errors. For all of this and more, take a look at the weather guide.

Changes to Watch Face development

As we gather momentum behind the Watch Face Format, we’re announcing some changes to existing watch face development options.

We announced recently that only some complications will be available on Wear OS 5, for watch faces built with AndroidX or the Wearable Support Library. This restriction does not apply to watch faces that use the Watch Face Format.

Additionally, starting in early 2025 (specific date to be announced in Q4 2024), all new watch faces published on Google Play must use the Watch Face Format. Existing watch faces that use other libraries, such as AndroidX or the Wearable Support Library, can continue to receive updates without transitioning to the new format.

New resources

To make it easier to create watch faces using the Watch Face Format, we’ve published some more resources on GitHub.

You now have full access to the XSD specification, to help you build your own watch face generating tools.

We’ve also provided validators to check your XML for correctness and memory usage. These are the same checks run by Google Play, so it allows you to run these checks even before you submit your watch face for publishing.

Learn more

Get started with the latest version of the Watch Face Format.

Be sure to check out Building for the future of Wear OS technical session and What’s new in Wear OS at I/O 2024 blog post to learn more about all the latest updates for Wear OS!

Code snippets license:

Copyright 2023 Google LLC.
SPDX-License-Identifier: Apache-2.0