Joplin

joplinapp.org

Open-source, encrypted note-taking app, an Evernote alternative synced across all your devices.

Strengths

A simple, effective task manager.

Organize your projects on boards of cards (kanban).

Let people book a slot in your calendar.

Infinite collaborative whiteboard for team brainstorming.

To-do lists and reminders synced across all your devices.

Open-source online scheduling: share your availability with one link.