Know any great free learning platforms?

[Scottbaday]

Not exactly the thread topic, but found something useful
 
Just while digging through educational sites I discovered a site https://tools.veryuseful.website.
 
They've collected:
- online libraries (like "Українська Література"),
- free courses via Prometheus,
- Duolingo for learning Ukrainian,
- information about schools and universities.
 
Saves a ton of search time.
 
Also found an awesome Ukrainian learning platform — maybe worth checking!
 
How do you boost your education?