Basically, this is a lecture for beginners who can handle Android Kotlin If it is your first time using Firebase, I can recommend it, but it is not detailed. If your goal is Firebase, I recommend another lecture Since it flows according to the flow of consciousness, I recommend listening to it all once and coding while going back rather than leaving it aside and following along Please note that following this lecture does not mean that you will get a neat app Be careful, as there are old codes mixed in, as in the review below