Readwise - Effortlessly rediscover and organize your Kindle highlights

Clippings.io - Organize the notes you make on your Kindle

Kindle Highlight Export by Glasp - Export all your highlights and notes from Kindle in 1-click

Kindleaf - Kindleaf helps you organize, search, and revisit your Kindle highlights in one calm, distraction-free space.

PastReads - Manage and review your book & web highlights from Kindle, Apple Books, and Kobo with PastReads. Upload, organize, and receive daily reminders for your reading insights.

Screvi - Screvi collects your lost and messy book highlights and turns them into something you'll actually use. Import all your kindle, twitter and physical book highlights and stop forgetting what you read.