I have gone through the first 10 challenges of the React tutorial, and I think it is wonderful. It seems to be very difficult to learn about this from other web-based materials, because even the “simplest” examples are complex and (for me) impossible to understand. (The tic-tac-toe example in git hub is a marvel of INcomprehensibility, for example.)
I do have some suggestions for several challenges, but I will post them separately, because here I want to say that this is an extremely useful tutorial and I would like to thank very much whoever created it. It shows a lot of thought and a lot of work.