Readwise - Effortlessly rediscover and organize your Kindle highlights
TotalFinder - TotalFinder is a plugin for Finder.app which adds tabs like in Chrome browser, dual panels similar to TotalCommander and more tweaks.
Clippings.io - Organize the notes you make on your Kindle
Path Finder - The Finder, reinvented. Path Finder is an award-winning file browser and management application for Mac OS X.
Knotes - An efficient, beautiful Kindle highlights & notes manager
Forklift - The most advanced dual pane file manager and file transfer client for macOS.