Binary Watch Face is a resource-only Wear OS face that presents hours, minutes, and optional seconds as true binary values. It is an independent implementation inspired by a retired face that no longer installs on newer watches.
The leftmost dot in each row is the most significant bit. Add the weights above the lit dots to read the value. For example, 23 is 16 + 4 + 2 + 1. Every row spans the same left and right endpoints while distributing its four, five, or six bits evenly between them.
- Offers direct 12- or 24-hour clock selection, defaulting to 24-hour mode
- Uses four hour bits in 12-hour mode, five in 24-hour mode, and six for minutes and seconds
- Offers optional full-dial decimal values, bit weights, a seconds row, multiple date formats, and decimal, hexadecimal, or binary watch-battery readouts
- Defaults dots and text independently to phosphor terminal green, with a broad palette and dark or light appearance
- Gives the decimal backdrop independent color, opacity, size, position, and active/AOD visibility controls
- Includes tiny through huge display sizes, none/glow/bezel dot effects, and none/single/wave/boost/all tick styles
- Provides two complications by default and configurable two-, three-, and four-slot layouts
- Preserves normal provider actions on complications without defining any whole-face or custom tap actions
- Uses dense patterned dots and the selected color in always-on display mode by default, with optional decimal values, date, weekday, and watch battery while keeping complications legible
The watch face uses Watch Face Format 5 and requires Wear OS 7, API level 37. Format 5 is required to let a setting enable exactly two, three, or four complication slots without leaving invisible tap targets. That compatibility choice favors Pixel Watch 5 and other Wear OS 7 watches over older devices.
Eligible testers can join the Google Play internal test for Play-managed installation and updates.
Download binary-watch-face.apk and binary-watch-face.apk.sha256 from the GitHub releases page. Release APKs are exported from Google Play and carry the same app-signing certificate as Play-installed builds.
Verify the download:
shasum -a 256 -c binary-watch-face.apk.sha256Install the latest Android SDK Platform Tools, then follow Google's Wear OS debugging instructions to enable ADB debugging and connect the watch over USB or Wi-Fi. Install the APK directly on the watch:
adb install binary-watch-face.apkInstall later GitHub updates without clearing the watch-face configuration:
adb install -r binary-watch-face.apkA locally built debug copy uses a different signing certificate. If ADB reports incompatible certificates, remove that copy before installing the release APK. Uninstalling clears its configuration:
adb uninstall dev.j256.binarywatchface
adb install binary-watch-face.apkAfter installation, long-press the active watch face, scroll to Add new, and select Binary.
Long-press the active face and choose Edit. Every choice names both the setting and selected value, such as Dots: Terminal green or Seconds: Hidden, and the package supplies a matching highlight overlay for editors that support it. Each enabled complication can be assigned through the normal Wear OS complication picker.
| Setting | Options |
|---|---|
| Dots color | Terminal green by default, plus white, warm colors, cool colors, greens, and grays |
| Text color | The same palette, selected independently and defaulting to terminal green |
| Theme | Dark by default or light |
| Backdrop color | The full palette, selected independently and defaulting to medium gray |
| Backdrop opacity | 15%, 30% by default, 50%, 75%, or 100% |
| Backdrop layout | Small, normal, or large at a raised, centered, or lowered position |
| Backdrop visibility | Active only by default, hidden, AOD only, or active and AOD |
| Size | Tiny, small, normal, large by default, or huge |
| Clock mode | 24-hour by default or 12-hour |
| Effect | None, glow by default, or bezel |
| Ticks | None, single, wave, boost, or all by default |
| Binary display | Optional seconds row and bit weights |
| Date | Nov 26, 11/26, 26 Nov, 26/11, 26.11, ISO, Unix timestamp, or hidden, with independent weekday and uppercase controls |
| Battery | Watch battery in decimal percent by default, hexadecimal, binary, or hidden |
| Complications | Two by default, three, or four |
| Always-on display | Optional date, weekday, and watch-battery presets, plus optional monochrome rendering |
The complication layouts keep the larger lower-left and lower-right providers stable when the count changes:
- Two: lower left and lower right
- Three: the lower pair plus a smaller lower center slot
- Four: the lower pair plus upper left and upper right
The build requires JDK 17, Python 3, and the standalone Android CLI. On macOS, $HOME/Library/Android/sdk is the standard SDK location. Install the project SDK packages with:
android --no-metrics sdk install platform-tools platforms/android-37.0 build-tools/36.0.0Add the emulator and signed Wear OS 7 image for device testing:
android --no-metrics sdk install emulator system-images/android-37.0/android-wear-signed/arm64-v8aAndroid CLI can start and manage an existing watch AVD, but its built-in emulator create command only accepts the hardware profiles shown by --list-profiles. Install the SDK command-line-tools component when a Wear profile is not listed, then create the AVD with avdmanager:
android --no-metrics sdk install cmdline-tools/latest
"$ANDROID_HOME/cmdline-tools/latest/bin/avdmanager" create avd \
--name binary_watch_face_api_37 \
--package 'system-images;android-37.0;android-wear-signed;arm64-v8a' \
--device wearos_large_round
android --no-metrics emulator start --cold binary_watch_face_api_37The SDK's avdmanager is used only for the Wear hardware profile. Package installation and emulator startup remain on Android CLI; the deprecated sdkmanager command is not needed.
Generate and build the resource-only APK and app bundle:
python3 tools/generate_watchface.py --check
./gradlew check assembleDebug bundleReleaseInstall the debug APK without launching an activity:
android --no-metrics install \
--device=emulator-5554 \
--apks=watchface/build/outputs/apk/debug/watchface-debug.apkOn the watch, long-press the active face, scroll to Add new, and select Binary. The release app bundle is written beneath watchface/build/outputs/bundle/release/.
Google Play App Signing owns the app-signing keys used on installed packages. Release bundles are signed locally with a separate, resettable upload key kept outside this repository. Set both signing variables to produce a signed upload bundle; leaving both unset preserves secret-free unsigned release builds for CI:
binary_watch_face_upload_password="$(security find-generic-password -a upload-keystore -s dev.j256.binarywatchface.upload -w)"
export BINARY_WATCH_FACE_UPLOAD_STORE_FILE=/absolute/path/to/upload-keystore.p12
export BINARY_WATCH_FACE_UPLOAD_PASSWORD="$binary_watch_face_upload_password"
./gradlew --no-configuration-cache bundleRelease
unset BINARY_WATCH_FACE_UPLOAD_STORE_FILE BINARY_WATCH_FACE_UPLOAD_PASSWORD binary_watch_face_upload_passwordVerify the resulting upload bundle before submitting it to Play:
jarsigner -verify -verbose -certs watchface/build/outputs/bundle/release/watchface-release.aabRun the generator tests, generated-file check, and Android build with:
python3 -m unittest discover -s tests -v
python3 tools/generate_watchface.py --check
./gradlew check assembleDebug bundleReleaseBefore publication, also run Google's Watch Face Format validator and Memory Footprint Evaluator:
java -jar /path/to/wff-validator.jar 5 watchface/src/main/res/raw/watchface.xml
java -jar /path/to/memory-footprint.jar \
--watch-face watchface/build/outputs/apk/debug/watchface-debug.apk \
--schema-version 5 \
--ambient-limit-mb 10 \
--active-limit-mb 100 \
--apply-v1-offload-limitations \
--estimate-optimizationThe GitHub Actions workflow repeats the deterministic generator checks and full Android build using Android CLI rather than sdkmanager.
The watch face contains no executable Android code, network access, analytics, or data-collection permissions. See PRIVACY.md.
Copyright 2026 James Klein
Licensed under the GNU Affero General Public License, version 3 only. See LICENSE.