Glenn Robert Strandos
Does not answer comments on course. Two years passed, still no answers. Does not update broken links for assets which the course is entirely based on - Meaning that the course is not possible to code alongside. I highly recommend not taking the course as it is entirely useless without assets. The author also mentions "Feel free to ask in the comments for this course", while this would be a great opportunity, it is not very convenient as you will never get a reply.
Compact but solid and well organized introduction to ObjC world.
Somewhere there are mistakes. For example, importing classes in header files. And somewhere there are strange things. For example, it is unclear, why we use mutable arrays for first and second column, but immutable for returning array at creating factory for tiles.
Great intro to the basics of Objective-C