Duck Duck Moose gave me a free redeem code for my class to try Puzzle Pop HD. Teachers at my school use some of their other apps and enjoy them.
Puzzle Pop is more of a "fun" app than a grammar or math app. However, there's lots of learning going on in the form of problem solving and thinking. My students played the app in pairs, so they also had to communicate with each other as they worked to solve the puzzles.
There are 27 puzzles in the app and they get increasingly more difficult. My students played for about 15 minutes total and collectively reached level 15-18. I only played the first level myself so after they played I asked them to explain to me what they had to do, what they liked, what was easy and what was challenging. It was a great conversation and I encouraged them to start their comments with "I agree with..." or "I also thought..." or "I didn't think...", something I have been working on with them. The comments were positive and they all want to play again, so I'm sure I'll be buying some copies soon!
Students both liked and were frustrated by some of the interactive features that appear as the levels get more difficult. For example, the characters move from 1 puzzle piece to another as students re-arrange them. Also, the screen goes dark at some points so all the player can see is the eyes of the characters in the puzzle. Since I haven't played myself (I did peek over shoulders) I can't comment directly, but these extra goodies sound like fantastic and creative ways to add challenge to a puzzle beyond just adding more pieces.