Annotate.tv - Optimize your learning on YouTube
Todoist - Todoist is a to-do list that helps you get organized, at work and in life.
Slid - Capture knowledge from online videos, courses, and webinars
TaskPaper - Plain text to-do lists for Mac
SkillTube - A curated list of best courses from YouTube & other platform
Listy Beta - The things you love, privately saved and beautifully listed