I am a current Android developer who is trying to switch to iOS developer. Alan's lectures go into detail about things I had overlooked. So I guess it added depth to the shallow knowledge I had... The textbook also explained the memory structure while drawing it, so I understood it really well. In fact, most current developers develop without knowing much (including me... hehe) While watching the lecture and the textbook, I could feel how much passion and effort Alan put into it. In fact, I think it is really difficult to study consistently because the lecture itself is done by one's own will. However, the 'Learning Progress Chart' and the 'sessions' that were held every week were big devices that allowed me to consistently take the class. *Learning Progress Chart: A shared document where you can see the progress of students in the same class at a glance -> When my progress is lagging behind or falling behind, I get motivated by seeing the progress charts of students who are working hard and listen hard. *Session: Meeting with students in the same class and Alan via video to review the week, share iOS outlook and information, etc. -> It was really informative and great because it was a time to review the lecture content I studied for a week. So it's not just a regular lecture, but a care-giving lecture..? I really liked it. The community is also very active. The lecture itself is of good quality, but it's a care-giving lecture... I highly recommend it.