How To Quickly Take Notes When Using Firefox
QuickNote is a simple and useful note taking add-on for Firefox. It can be used to quickly take notes and save them if needed.
Download and install it from here.
After it is installed, the QuickNote icon will show up next to the search bar. Clicking on it opens the notes.
The settings for how these notes are displayed (whether floating, or as a sidebar, or as a new tab) and much more can be configured...