Readwise - Effortlessly rediscover and organize your Kindle highlights
Highly for iOS - Medium-style highlighting in every app and website. 🖌
Clippings.io - Organize the notes you make on your Kindle
LINER - LINER AI Copilot is currently powered by ChatGPT/GPT-4, Google Search Engine, and information from high-quality highlights of an enormous number of users from all around the world.
Knotes - An efficient, beautiful Kindle highlights & notes manager
Weava - Workspace to highlight, organize & collaborate on your research articles.