I use this for sharing notes with colleagues that are not data sensitive. Great collab features. Sadly, no encryption available. Otherwise, it works like a charm.
I really like Simplenote because it is simple, no big features, just simple notes that can be organized by creating tags. This clean and minimalist tool helps me focus 100% on my notes, which is exactly what I was looking for.
After using Apple Note, OneNote, Evernote, SimpleNote ends up to be my default note app, despite (or maybe *because of*) its seemingly lacking of advanced features.