BusyMax is a beta calendar and task manager for Android, Linux, and Windows. It brings events, tasks, reminders, and day, week, month, year, and agenda views into one application.
Linux uses a Yaru/GTK desktop composition with XDG integrations. Windows uses a separate Fluent composition with a native Windows title bar, tray, notifications, and packaged startup integration. Android uses a separate adaptive Material 3 composition, native account authorization, WorkManager, Android notifications, and the Storage Access Framework. Provider capabilities differ; see the provider support matrix before relying on a particular task field or operation.
Month view in the Linux desktop application.
- Calendar and task planning in day, week, month, year, and agenda views.
- Direct connections to Google, Microsoft, Apple iCloud Calendar, and Nextcloud, plus read-only WebCal subscriptions.
- Event and task editing that follows each provider's supported fields and the permissions granted for a collection.
- Local caching for offline viewing. Supported changes can be queued for some providers; offline behavior is not identical across every integration.
- Platform-native reminders, Android document import/export, desktop tray actions, themes, keyboard navigation, and localized interfaces.
More Linux screenshots
 Week view |
 Day view |
 Agenda view |
 Year view |
 Task editor |
 Event editor |
 Account providers |
The public packaged release is the Linux beta in the Snap Store. The repository does not document a public production Windows download or Store listing. Windows maintainers can build and install a test-signed package by following the Windows packaging guide; unsigned CI packages are test artifacts, not ordinary user downloads.
Packaged users do not need Flutter, Visual Studio, Linux development libraries, or their own OAuth registration. In a configured build:
- Desktop Google and Microsoft accounts connect through browser-based sign-in. Android uses Google Play services authorization for Google and MSAL's registered browser redirect for Microsoft.
- Apple iCloud Calendar uses an Apple app-specific password; Apple Reminders is not supported. See Connect Apple iCloud Calendar.
- Nextcloud authorizes BusyMax in the default browser and requires a compatible HTTPS server. See Connect Nextcloud Calendar and Tasks.
- WebCal adds a read-only calendar subscription from a confirmed URL.
Developers who need to configure their own desktop OAuth applications should use the Google OAuth registration guide or Microsoft OAuth registration guide. Provider differences and limitations are summarized in the provider support matrix.
Android support targets API 37 with a minimum API of 24 and uses the explicit
entrypoint lib/main_android.dart. It requires Flutter 3.47.4, bundled Dart
3.13.3, JDK 17, Android platform 37, and Build Tools 37.x.
tool/android/check_prerequisites.sh
cp android/busymax.android.properties.example android/busymax.android.properties
tool/android/run.sh --device DEVICE_IDThe copied public configuration needs real Microsoft and certificate-specific provider registrations before those sign-in flows work. It contains no client secret. See Android setup, Android release, and the Android verification report. Generated test-signed artifacts are not production releases.
Account, provider, and data information:
- Provider support matrix
- Apple iCloud Calendar setup
- Nextcloud Calendar and Tasks setup
- Privacy and data map
- Android setup and OAuth registration
- Android provider parity
Development and maintenance:
- Development setup for Linux and Windows
- Linux window and rendering architecture
- Android release, verification, and implementation status
- Google developer OAuth registration and Microsoft developer OAuth registration
- iCalendar and DAV data model
- Live-provider testing
- Windows architecture
- Snap beta release
- Windows packaging and release checklist
- Maintenance tools and vendored dependencies
Report defects and request features in the BusyMax issue tracker. The in-app Send feedback action submits only the fields described in the privacy and data map; optional technical details are off by default.
BusyMax is licensed under the Apache License 2.0. See NOTICE for attribution and trademark information.