My friend is really a puzzle enthusiast. He's very geek. He likes solving puzzles and the puzzles that he solves are just among the hardest I have ever come to encounter in my life. And those puzzles I consider impossible to be solved he finds just challenging enough to take time playing them and eventually solving them. I don't know yet anything that he was not able to solve. And since he plays puzzles on his iPad. That's what he does all day and all night, I am thinking of buying an app for him, a puzzle app. But I don't know, and not sure which particularly. I just need one criterion. It has to be as difficult as impossible to be solved for many, for the majority. That's it and nothing much more else.
Checkout 'TheLog In on App store. The gameplay is really simple and pretty straightforward. It consists of a fast moving square through a level and as you make your square jump over smashing objects the game becomes more exciting. Take my warning, it is insanely addictive.