Tuta Calendar
Tuta Calendar is a free, open-source calendar and contacts app for Android and iOS. Quantum-safe encrypted planner to schedule & manage your events & sync calendars. It has 7,986 GitHub stars and is released under the GPL-3.0-or-later license, and you can install it from F-Droid, Google Play and the App Store.
About Tuta Calendar
Take your privacy to the next level with the secure Tuta Calendar app. This encrypted time-management tool is the most private way to organize your busy schedule – and it’s quick to navigate, comes with dark and light mode, plus, it’s perfectly integrated with the Tuta Mail app. SECURE CALENDAR * Quantum-safe encryption: End-to-end encrypted data exchange with all Tuta Calendar users and with users of other calendar apps (via optional password-protected event invites). * No ads, no tracking, and no data sharing: We protect your privacy. * Zero-knowledge architecture: Entire events, including event notifications, are encrypted and hidden from our servers.
Privacy and F-Droid
F-Droid builds Tuta Calendar from its published source code and flags anti-features such as ads, tracking or reliance on non-free services.
- Relies on a non-free network service
Screenshots
Screenshots from the app's F-Droid listing.
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What is Tuta Calendar?
Tuta Calendar is a free, open-source calendar and contacts app for Android and iOS. Quantum-safe encrypted planner to schedule & manage your events & sync calendars. It has 7,986 GitHub stars and is released under the GPL-3.0-or-later license, and you can install it from F-Droid, Google Play and the App Store.
Is Tuta Calendar free and open source?
Yes. Tuta Calendar's source code is public on GitHub under the GPL-3.0-or-later license, which is OSI-approved or FSF-free. F-Droid flags these anti-features on its latest build: relies on a non-free network service.
How do I install Tuta Calendar?
You can install Tuta Calendar from F-Droid (package de.tutao.calendar), from Google Play and from the App Store; the links are on this page. Its GitHub repository also publishes releases (latest: tutamail-nextcloud-release-1.2.3612610060).
Is Tuta Calendar still maintained?
The repository's most recent commit was on Oct 6, 2026. Its F-Droid listing was last updated on Sep 26, 2026. appsgit only lists apps whose repository had a commit in the last six months.