Evernote Tweaker is a Chrome extension that makes minor tweaks to the Evernote web client to enhance usability. It focuses on improving note editing functionality on Evernote.com by addressing unresolved defects. By adding JavaScript listeners to the page during note editing, this extension aims to enhance the user experience.

The primary issue currently addressed by Evernote Tweaker is the unexpected removal of empty lines when pasting code with an empty line into an Evernote codeblock. This behavior can make code less readable and lead to potential errors. The extension ensures that empty lines are retained and saved in the note by incorporating appropriate metadata.