Simplenote - Free, Rock Solid and Dependable for Over a Decade

Simplenote by Automattic is a free cross-platform plain text / Markdown notes app for macOS, iOS, Android, Windows and Linux. It's been around for over a decade and I have never known it to go down. Automattic is the company behind Word Press and Day One, so it's no fly-by-night enterprise. 

One of the primary benefits of using Simplenote is the speed. It syncs behind the scenes and opens quickly, regardless of platform. Each note has a history, and you can view changes you've made to it over time. Notes are easy to share on a Mac using the system share sheet. If you don't have access to a device on which you have Simplenote installed, you can get to your notes in a browser. 

Notes in Simplenote are organized by tags. Use as many as you want. You can also do simple searches of your notes via text strings. Simplenote is compatible with Apple's new writing tools, which means you have access to dictation, proofreading, rewriting, spelling and grammar correction. Information about each note, including creation date, modification date, character count and word count is available at the click of a button. Like most modern apps, Simplenote has a light and dark mode. You can also control the default text size. Important notes can be pinned to the top of your notes list. 

The Simplenote API is open to developers. There are several other note-taking apps on various platforms that can access your notes database. On such app is nvPY for macOS.