The people at Coursera advertise the module as a free course. Only after finishing your first assignment did I realise, that I have to pay to submit! Why advertise it in the first place as a free course? I felt really gutted because I invested a few hours in this assignment and then nothing. I cannot afford to pay what they want me to, in order to continue with my course. It's just a sneaky tactic they are using to get new customers. In addition, the first part, which I could complete, the theory part, wasn't useful at all. They talked about the ordinary stuff you hear in every other youtube video. I don't recommend the course at all.