If anyone has interest in practicing these, there is some nice software: CT-Art that was just a tremendous help to me. It focuses on "motifs", where instead of most puzzles that ask you to "find the next move" you see the position a few moves out from the desired pattern so you learn to recognize what it looks like and learn to steer it into that pattern when it's not staring you in the face.
They (Chess King) have many apps that overlap in functionality, it can be a bit confusing...
I think that probably they have a separate app for every course, but all the courses are also available in a single app.
