BusyMax is a Linux and Windows desktop calendar and task manager built with Flutter.
It brings calendar events and tasks into a native-feeling desktop interface: Yaru with the existing GTK integrations on Linux, and Fluent UI with the native title bar on Windows 11. BusyMax connects directly to Google, Microsoft, Apple iCloud Calendar, and Nextcloud. Apple Reminders is not supported.
Month view with calendars, tasks, and event details.
- First-class Linux Yaru and Windows 11 Fluent desktop applications.
- Calendar views for day, week, month, year, and agenda planning.
- Task creation with lists, start/due dates, reminders, repeat options, subtasks, status, progress, priority, categories, location, and URL.
- Nextcloud task-list creation/rename/delete, recursive task duplicate/delete, raw iCalendar export, clear-completed, and cross-list subtree moves.
- Event editing with calendar selection, time controls, repeat rules, and reminders.
- Ordinary event and supported-task location fields, with a saved destination opened on demand in an external maps application or browser.
- Tray shortcut for opening the main Agenda view.
- Direct integrations with Google Calendar, Google Tasks, Microsoft Calendar, Microsoft To Do, Apple iCloud Calendar, Nextcloud Calendar, and Nextcloud Tasks.
- Offline-first local cache, conditional DAV writes, recurrence exceptions, alarms, and explicit conflict handling for CalDAV accounts.
Week view with color-coded calendars and scheduled tasks. |
Day view for focused daily planning. |
Agenda view with upcoming events, tasks, and details. |
Task creation with lists, due dates, reminders, and repeat options. |
More screenshots
- Flutter SDK
- Flutter is pinned to 3.47.2 for both platforms (bundled Dart 3.13.2).
- GTK 3 and libhandy development packages (
libgtk-3-devandlibhandy-1-devon Ubuntu/Debian) GOOGLE_OAUTH_CLIENT_IDandGOOGLE_OAUTH_CLIENT_SECRET; see Google setupMICROSOFT_OAUTH_CLIENT_ID, see Microsoft Setup
Apple and Nextcloud do not require compile-time client credentials:
- Apple iCloud Calendar setup requires two-factor authentication and an Apple app-specific password.
- Nextcloud setup requires an HTTPS server and completes authorization in the default browser.
Windows targets Windows 11 24H2 or newer on x64 only. See Windows development for Visual Studio and SDK requirements, exact development commands, and the source-side validation workflow.
Register the development launcher once so GNOME can associate BusyMax's native Wayland windows with its desktop icon. The helper is idempotent and defaults to the Flutter debug bundle:
tool/install_linux_dev_desktop.shThen run BusyMax normally:
flutter run -d linux -t lib/main_linux.dart \
--dart-define=GOOGLE_OAUTH_CLIENT_ID=<google-client-id> \
--dart-define=GOOGLE_OAUTH_CLIENT_SECRET=<google-secret-if-needed> \
--dart-define=MICROSOFT_OAUTH_CLIENT_ID=<microsoft-client-id>Locations are stored as ordinary calendar/task data. Show on map hands a
saved address or point to the registered maps handler on Linux, with a Google
Maps browser-search fallback, and to the default browser on Windows. A complete
HTTP(S) location is opened directly as Open link. BusyMax has no embedded
map, address autocomplete, mapping account, or mapping API-key requirement.
Provider-native coordinates remain in Microsoft structured locations and
iCalendar GEO. When importing or copying a point into Google Calendar, which
has only free-form location text in this workflow, BusyMax retains a local
supplemental point for the exact saved event or provider series. A later
recurring occurrence can reuse the series point only while its saved location
still matches; an occurrence-specific point takes precedence. Supplemental
series data follows a Google This and following split only when the new
series keeps that location; the earlier series retains its own association.
points are not uploaded through Google Calendar and therefore are not
automatically available on another BusyMax installation.
Use tool/install_linux_dev_desktop.sh --uninstall to remove the development
launcher. Remove it before testing an installed Snap so the user-level launcher
does not take precedence; packaged Snaps register their own launcher.
The native Send feedback form in the About dialog sends JSON to
POST https://busystack.org/api/feedback. Every submission contains a new
submission UUID, the application identifier busymax, the application version
and build number, the runtime platform identifier, category, subject, message,
and optional reply email. A successful response has this form:
{ "id": "server-reference-id" }The optional technical-details checkbox is off by default. When the user explicitly enables it, BusyMax adds only the operating-system version and application locale. BusyMax does not attach logs, account or calendar data, file names, screenshots, environment variables, tokens, or other diagnostics.
For local website development, override the endpoint through the existing compile-time configuration mechanism:
flutter run -d linux \
--dart-define=BUSYSTACK_FEEDBACK_ENDPOINT=http://127.0.0.1:8090/api/feedbackThe local Snap helper accepts the same value with
--dart-define BUSYSTACK_FEEDBACK_ENDPOINT=http://127.0.0.1:8090/api/feedback.
No API, CAPTCHA, or other private server credential is used by the desktop
application.
The provider capability matrix lists the features and limitations of each integration. Maintainers can use the live-provider test guide for opt-in Nextcloud and iCloud integration tests.
See Snap Build and Beta Release for OAuth build configuration, canonical Snapcraft packaging, local installation, artifact verification, Store review, and beta release instructions.
Windows uses the separate lib/main_windows.dart entrypoint and a Fluent UI
composition. Linux continues to use lib/main_linux.dart, Yaru, GTK, the XDG
tray, and the existing Snap package. The Windows Store MSIX workflow is local
and CI-only; it never deploys an artifact.