I recently came across with Saber, a cross platform notes/drawing app (supports Android, iOS, Linux, macOS, Windows and there is also an web app) that supports synchronization using Nextcloud.
It is available as an appimage (and also flatpak and snap). It would be great if it is available in the AUR/official Manjaro repositories. This app is written in Flutter.
With powerful devices like PineTab2 and PineNote (which run Arch based operating systems) coming soon, this app will be a good substitute for proprietary services like OneNote (and similar note-taking software running on an iPad).
Note: I am not the author of this app.