Because you all need to know this

There's a GemCraft iPhone app. It is more similar in gameplay to the older GemCrack games, not GemCrack Labyrinth. The free version has 5 levels, in each you can play 3 styles, and there are three difficulty levels. I haven't yet tried the paid version, I'm waiting till I beat the free version (I tend to spend too much money in general, so I try to spend as little as possible on video games). The interface is okay, but of course a bit more kudgy than a mouse and hotkeys. I recommend hovering one finger over the pause button. On the iPad you can tell it's not using the full resolution, but that doesn't significantly reduce its addictiveness.