Cross-Platform Apps
Productivity
- calendar: OneCalendar / Proton Calendar
OneCalendar is closed-source whereas Proton Calendar is open-source. Proton Calendar requires using Proton Mail, however. If you don’t like either, I would recommend the Android and iOS specific calendar apps.
Joplin, Logseq, and Notesnook are open-source whereas Obsidian is closed. All of them offer syncing options. Logseq interestingly doesn’t use a folder-based structure like Obsidian does, but both use .md files.
Joplin and Notesnook don’t use .md files or similar, but the latter allows you to export your notes as text files (.txt, .pdf, .html, and .md). There is a Joplin plugin that allows you to save notes as .md files called “Save as .md”. This feature should really be built in though.
Other note-taking apps are also great, it just depends on your personal preference. The ones I have listed here are options that I have tried that have good UI, syncing between devices, and Markdown support in some form or another.
- office suite: Collabora Office
Social
- Mastodon: official app
- Lemmy: Voyager
Navigation
- maps
- standard: Organic Maps
- more features: OsmAnd
- public transport: Transit
Utilities
- file sharing: KDE Connect
- screen mirroring and extending: spacedesk