Not necessarily mate in 2

I bought the mate in 1 pack, and was quite impressed, so I bought mate in 2. Unfortunately, many of these puzzles are mate in more than 2. The app assumes black will make a specific move in response to whites first move.. And yes, if we permit that, then it will mate in 2. However, in many cases if black were to make another move (other than that programmed by the app), then the mate will take several more moves, or not at all.

Pauleduc about Mate in 2 Chess Puzzles, v2.5