Move the Box starts off with a few very simple levels to teach you how the game works. You can move, drop and swap the boxes. Three or more boxes of the same kind in a line disappear.
So what's the catch? You only have a limited number of moves in each level.
So, for example, you may only need to swap two boxes to have them line up 3 matching boxes which then disappear, the boxes on top of them fall and line up themselves, etc...
The goal in each level is to move the boxes in less than the number of allowed moves, in order to clear all the boxes in the level.
After the first few levels you'll see that it quickly gets more complicated.
The graphics are nothing spectacular but ok (they tried to go for a style that resembles Angry Birds) and the sound is pretty solid.
Move the Box Pro is currently free and is compatible with iPhone, iPod touch, and iPad (they also have a "lite" which will probably remain free).