Notenik is an awesome note-taking app for Mac users. It's free, open-source, and stores your notes in plain text, so you can open and edit them with any text editor.

You can use cool features like Markdown for formatting and creating different fields for organizing your notes. It plays well with other tools, allowing you to import, export, and publish your notes easily.

Plus, it's thoroughly documented and actively supported by its developer, Herb Bowie. People love its clean interface and flexibility. If you want a powerful yet simple note-taking app, Notenik is perfect!