QOwnNotes
QOwnNotes is a plain-text file notepad and todo-list manager
...Because all notes are stored as markdown files in user-controlled directories, you avoid vendor lock-in and can sync through services like Nextcloud, ownCloud, Dropbox, or Git without proprietary cloud dependency. The application is optimized for performance and minimal footprint, so it runs smoothly even with large note libraries, and it includes features like a live markdown preview panel that lets you see rendered text alongside raw markdown as you type. QOwnNotes supports hierarchical folders and tagging, making it easy to organize, filter, and retrieve information quickly, and it also integrates to-do lists and task markers directly in your notes.