Circadian Display

Adaptive screen warmth and dimming curves for better evening comfort and sleep.

New in version 1.0.2

- Overlay Mode: the warmth/dimming layer no longer blocks touches on Android 12+
- Native Mode: colour temperature now clamps to your device's supported range, fixing a black screen on some devices

Circadian Display continuously adjusts your screen's warmth and brightness throughout the evening based on customizable curves you define. Unlike standard night light solutions with fixed on/off schedules, Circadian Display provides a smooth, gradual transition tailored to your preferences.

Features:
- Dynamic comfort curves with precise warmth and dimming levels over time
- Dual-engine modes: Native (system-level, Android 10+ with ADB setup) and Overlay (software-based, works on all devices)
- Background scheduler for automatic, hands-free operation
- Privacy-first: completely offline, tracker-free, no data collection
- Open source (Apache 2.0)

Versions

Although APK downloads are available below to give you the choice, you should be aware that by installing that way you will not receive update notifications and it's a less secure way to download. We recommend that you install the F-Droid client and use that.

Download F-Droid

Version 1.0.2 (3) suggested Added on Sep 20, 2026

arm64-v8a armeabi-v7a x86 x86_64

This version requires Android 8.0 or newer.

It is built and signed by F-Droid, and guaranteed to correspond to this source tarball.
Permissions
- run foreground service
  
  Allows the app to make use of foreground services.
- android.permission.PACKAGE_USAGE_STATS
- run at startup
  
  Allows the app to have itself started as soon as the system has finished booting. This can make it take longer to start the phone and allow the app to slow down the overall phone by always running.
- ask to ignore battery optimizations
  
  Allows an app to ask for permission to ignore battery optimizations for that app.
- This app can appear on top of other apps
  
  This app can appear on top of other apps or other parts of the screen. This may interfere with normal app usage and change the way that other apps appear.
- prevent phone from sleeping
  
  Allows the app to prevent the phone from going to sleep.
- android.permission.WRITE_SECURE_SETTINGS
- com.circadiandisplay.app.DYNAMIC_RECEIVER_NOT_EXPORTED_PERMISSION
Download APK 3.4 MiB PGP Signature | Build Log

New in version 1.0.1

- Clarified that Native (Hardware) mode requires Android 10+ (API 29+)
- Split native-mode error messages so API-level and ADB-permission issues are reported separately
- Removed the unused ACCESS_NETWORK_STATE permission pulled in by WorkManager

Version 1.0.1 (2) - Added on Sep 15, 2026

arm64-v8a armeabi-v7a x86 x86_64

This version requires Android 8.0 or newer.

It is built and signed by F-Droid, and guaranteed to correspond to this source tarball.
Permissions
- run foreground service
  
  Allows the app to make use of foreground services.
- android.permission.PACKAGE_USAGE_STATS
- run at startup
  
  Allows the app to have itself started as soon as the system has finished booting. This can make it take longer to start the phone and allow the app to slow down the overall phone by always running.
- ask to ignore battery optimizations
  
  Allows an app to ask for permission to ignore battery optimizations for that app.
- This app can appear on top of other apps
  
  This app can appear on top of other apps or other parts of the screen. This may interfere with normal app usage and change the way that other apps appear.
- prevent phone from sleeping
  
  Allows the app to prevent the phone from going to sleep.
- android.permission.WRITE_SECURE_SETTINGS
- com.circadiandisplay.app.DYNAMIC_RECEIVER_NOT_EXPORTED_PERMISSION
Download APK 3.4 MiB PGP Signature | Build Log

New in version 1.0.0

- Initial public release
- Custom circadian warmth and dimming curves
- Dual display engine: Overlay Mode and Native Mode (via WRITE_SECURE_SETTINGS)
- Automatic background scheduling every 15 minutes
- Completely offline, privacy-first, zero trackers

Version 1.0.0 (1) - Added on Sep 09, 2026

arm64-v8a armeabi-v7a x86 x86_64

This version requires Android 8.0 or newer.

It is built and signed by F-Droid, and guaranteed to correspond to this source tarball.
Permissions
- view network connections
  
  Allows the app to view information about network connections such as which networks exist and are connected.
- run foreground service
  
  Allows the app to make use of foreground services.
- android.permission.PACKAGE_USAGE_STATS
- run at startup
  
  Allows the app to have itself started as soon as the system has finished booting. This can make it take longer to start the phone and allow the app to slow down the overall phone by always running.
- ask to ignore battery optimizations
  
  Allows an app to ask for permission to ignore battery optimizations for that app.
- This app can appear on top of other apps
  
  This app can appear on top of other apps or other parts of the screen. This may interfere with normal app usage and change the way that other apps appear.
- prevent phone from sleeping
  
  Allows the app to prevent the phone from going to sleep.
- android.permission.WRITE_SECURE_SETTINGS
- com.circadiandisplay.app.DYNAMIC_RECEIVER_NOT_EXPORTED_PERMISSION
Download APK 3.4 MiB PGP Signature | Build Log

Versions

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