Recently I was graduated from react nanodegree with Udacity.
The course was separated into 3 main course:
1) React Fundamentals
2) React & Redux
3) React Native
Each course have their own assignment to complete, overall its about 4 or 5 months course, it only took me 1 month plus to complete 😉 since the course itself is little like mix of self pace or not.
You can submit your assignment on their web IDE or on github. The course cost $499 USD, but I would say its quite worth it, the course will assign a mentor to you, you can ask them questions related to the course, they should be happy to answer, sometime if you have different timezone when them, it takes a while for them to reply, but they also have a slack channel where you can ask questions over the channel with other students and some mentors.
Sometime the quiz they gave was pretty tricky, but that helps you think deeper and was overall experience was pretty good.