Whimsical Sticky Notes - Visual project management using sticky notes
FiveNotes - One-click Mac menubar notes app with fives easily accessible notes.
Jot - The no-fuss way to take notes
Jot menubar notes - Open-source freemium notes app for Mac menubar.
Gone - An ephemeral to-do list
FlowNote for Mac - The simplest yet clever Mac menubar note.