This is one of the most complete projects that you can find on the net to learn about bockchain in general, in addition to obtaining certifications according to the course you decide to take.
-In addition to offering learning services also business solutions.
-Large library with exclusive content. (especially related to business services.)
The only problem is that it focuses on the development of its app and services related to R3.
What I like the most about this project is that at the end you can take an exam and receive a certification that demonstrates your knowledge in blockchain development.
If you are at an advanced level this is a good alternative to consider, although you receive certification there is little generalized data.