UpNote - A beautiful and clean cross-platform app for notes organizer
Stickies - Stickies is a PC utility written to replace Post-It-style notes left stuck to your monitor.
Quillnote - Take beautiful markdown notes and stay organized with task lists.
Scrawl - Scrawl is a notes taking and memo app that lets you keep track of the things that are important for you, like daily routine tasks, projects, reminders, calculations, or accountability of someone.
Turtl - The secure, collaborative notebook
Pystickynote - Stickynotes for your desktop easily from the command line.