Adds notes managed by tagging without hierarchized tree to sidebar.
Simple notes in a panel, with a context menu item to copy text to a note.
Old school opera notes
The extension allows you to quickly save text notes on the sidebar of your browser.
Nimbus Notes - The easiest way to taking notes and clip text/pictures from Web pages in Opera browser.
Sidebar Sticky Note
Free HTML5 Sidebar Sticky Notes
Category Tabs for Google Keep™
Better organise your Google Keep notes
A Notepad for quick notes in your browser.