Recently I posted on Sticky Notes for Chrome browser. Well, good news! There’s a similar app for firefox.
Internote allows you to create useful and private notes on webpages which will be there once you return.
According to the extension download site, “With Internote, you can move, resize, recolor, minimize, import, export, print, delete your notes ... choose the pages where a note appears ... or manage them all at once.”
So, is it secure? Yes, it is as you’re putting the note/s on a layer “above” the webpage and it/info is never “uploaded”.
In the screen shot, you see Sticky Note for Chrome post in Fire Fox and the red arrow points to a small yellow square at the bottom of the browser window which you click to produce the Internote and configure it.
Link to Internote extension for Firefox