Excellent collection of 2-move problems
The price is very reasonable for the over 1000 problems you get to solve. The only thing I would suggest for improvement is the ability to try alternative lines - this would lead to full enjoyment of the problem. They are supposed to be tough to solve but most have stunningly beautiful logic and often surprising key moves.
valentine_00 about
Mate in 2 Chess Puzzles, v2.6