Joplin - Joplin is a free, open source note taking and to-do application, which can handle a large number of notes organised into notebooks. The notes are searchable, tagged and modified either from the applications directly or from your own text editor.
Monkkee - Keep a private journal securely on the Internet – to provide a convenient user experience your...
Boostnote - Boostnote is an open-source note-taking app.
Idea Notebook - Idea Notebook is an app that allows you to keep track of your logs business ideas and track as well as organize them.
Standard Notes - A safe place for your notes, thoughts, and life's work
RunaBook - RunaBook is a lightweight application that lets you create and organize notes, knowledge bases, and daily routines.