F-Droid Search: sync

Minimalist Markdown diary with app lock and your-own-cloud WebDAV sync.GPL-3.0-only

Ebook reader: EPUB on your phone, in sync with your own book serverMIT

Secure, Free and Open Source 2FA TOTP Authenticator App with Sync and Web AccessAGPL-3.0-only

Client-side encrypted notes that sync across devices.AGPL-3.0-only

Local-first multiplatform link organizer with optional self-hosted sync.MIT

Private, ad-free task lists! Optional sync with Google Tasks, CalDAV or EteSync!GPL-3.0-only

Sort, tag & sync your lists – encrypted on your own server.GPL-3.0-or-later

Stingle Photos is a secure, end-to-end encrypted gallery and sync appGPL-3.0-only

Cross-platform app to take notes. Encrypted, open-source, sync across devices.GPL-3.0-only

Open-source, local-first music player for music you own. No forced sync.MPL-2.0

Another notes app, like there have been tens of thousands before.Apache-2.0

Manage your finances on-the-go, encrypted for security, sync via your storage GPL-3.0-or-later

Shopping list and weekly planner with local syncMIT

A note taking and to-do app with sync between Linux, macOS, Windows, and mobileMIT

Quantum-safe encrypted planner to schedule & manage your events & sync calendarsGPL-3.0-or-later

Meditation timer with session log, stats, and Nextcloud syncGPL-3.0-or-later

Sync Android notifications encrypted to a Linux desktopGPL-3.0-only

Self-hosted Markdown notes with git sync, LAN sharing, and SQL scriptingMIT

Peer-to-peer amateur-radio field logbook that syncs with the xlog2 desktopGPL-3.0-or-later

your Taskwarrior Android companionGPL-3.0-only