Hello,
I have got my responsive web design certificate and i wanted to share my opinion, i think what differentiates freeCodeCamp from other tutorial websites is that they make sure you truly deserve to have the final certificate by proving yourself capable of working on the required projects. I think what’s also cool is that they don’t hold your hand too much while working on the projects, they just give you a set of user stories and you’ll have to do some digging on your own if you’re stuck on something, i personally came back to the courses when i forget about something or feel i need to brush up on it, i also checked external sources when needed. Unlike other websites where you can watch videos and do some easy and guided tasks to get the certificate, with freeCodeCamp you will feel that you have worked hard and achieved something when you get the certificate! 
I’m looking forward to starting with Javascript Algorithms and Data Structures!