PM - Like many game genre, Tetris style game apps are a plenty for the iPad. I like this EA (Electronic Arts) version in HD. It's an old game (I remember playing on a black and white 9 inch Apple Mac in 1992!) but with the added colour it just gets better.
Some visual stratagic mathmathical spatial awareness thinking is needed to fit the shapes in as best as you can to keep them from hitting the top fo the screen. Enjoy! :-)