When you highlight something on your Kindle, it goes into My Clippings.txt file and it is not grouped by a book. This is inconvenient. This React app parses the txt file and groups your notes by a book and exports them in a nice human readable format. All of this happens locally and your data is not sent to the Internet.
https://becausecurious.me/kindle_clippings_parser
In the project directory run npm start.