Hackr.io - There are tons of online programming courses and tutorials, but it's never easy to find the best one. Try Hackr.io to find the best online courses submitted & voted by the programming community.

Readwise - Effortlessly rediscover and organize your Kindle highlights

Tutset - Curated list of the best programming tutorials on the web.

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

Always Learning - The best resources for learning programming and design

Knotes - An efficient, beautiful Kindle highlights & notes manager