Readwise - Effortlessly rediscover and organize your Kindle highlights
Newsletters to Kindle - Read your newsletters on your Kindle
Clippings.io - Organize the notes you make on your Kindle
Knotes - An efficient, beautiful Kindle highlights & notes manager
Kindle Higlights - Remember what you highlighted on your kindle, once a week
Tressel.xyz - Save content from the Internet (like Twitter & Reddit) and export it to Notion, Obsidian & Evernote