iPad Finger Twister
Thanks to the increased size of the iPad, there have plenty of apps that utilize the tablet as a defacto game board, and it's not hard to see a group of friends crowding around it, taking turns in some digital version of their favourite games. Enter Fingstar. While not exclusively a party game, this looks like it would be more fun with at least one other person if not more, as you try and accomplish what the game asks of you in increasingly difficult ways. Have a look at this gameplay trailer to see what I mean.
The game is due out sometime around the 18-22 of December.