2.4. Watch Requirements

An Android Watch device refers to an Android device implementation intended to be worn on the body, perhaps on the wrist.

Android device implementations are classified as a Watch if they meet all the following criteria:

  • Have a screen with the physical diagonal length in the range from 1.1 to 2.5 inches.
  • Have a mechanism provided to be worn on the body.

The additional requirements in the rest of this section are specific to Android Watch device implementations.

2.4.1. Hardware

Screen Size (Section 7.1.1.1)

Watch device implementations:

  • [W-0-1] MUST have a screen with the physical diagonal size in the range from 1.1 to 2.5 inches.

Navigation Keys (Section 7.2.3)

Watch device implementations:

  • [W-0-1] MUST have the Home function available to the user, and the Back function except for when it is in UI_MODE_TYPE_WATCH.

Touchscreen Input (Section 7.2.4)

Watch device implementations:

  • [W-0-1] MUST support touchscreen input.

Accelerometer (Section 7.3.1)

Watch device implementations:

  • [W-SR] Are STRONGLY RECOMMENDED to include a 3-axis accelerometer.

Bluetooth (Section 7.4.3)

Watch device implementations:

  • [W-0-1] MUST support Bluetooth.

Minimum Memory and Storage (Section 7.6.1)

Watch device implementations:

  • [W-0-1] MUST have at least 1GB of non-volatile storage available for application private data (a.k.a. “/data” partition)
  • [W-0-2] MUST have at least 416MB memory available to the kernel and userspace.

Microphone (Section 7.8.1)

Watch device implementations:

  • [W-0-1] MUST include a microphone.

Audio Output (Section 7.8.1)

Watch device implementations:

  • MAY but SHOULD NOT have audio output.

2.4.2. Multimedia

No additional requirements.

2.4.3. Software

Watch device implementations:

  • [W-0-1] MUST declare the feature android.hardware.type.watch.
  • [W-0-2] MUST support uiMode = UI_MODE_TYPE_WATCH.

Search (Section 3.8.4)

Watch device implementations:

  • [W-SR] Are STRONGLY RECOMMENDED to implement an assistant on the device to handle the Assist action.

Accessibility (Section 3.10)

Watch device implementations that declare the android.hardware.audio.output feature flag:

  • [W-1-1] MUST support third-party accessibility services.

  • [W-SR] Are STRONGLY RECOMMENDED to preload accessibility services on the device comparable with or exceeding functionality of the Switch Access and TalkBack (for languages supported by the preloaded Text-to-speech engine) accessibility services as provided in the talkback open source project.

Text-to-Speech (Section 3.11)

If Watch device implementations report the feature android.hardware.audio.output, they:

  • [W-SR] Are STRONGLY RECOMMENDED to include a TTS engine supporting the languages available on the device.

  • [W-0-1] MUST support installation of third-party TTS engines.