Objective Development Software has released their first iPhone game,
Pebbles (http://www.obdev.at/pebbles/). The game is being made
available for free as an introductory offer until May 5 in the Apple
App Store. From then on it will cost US$2.99.

Here's how the game is described: "The basic principle of the game is
irresistibly easy: from the edge, you throw a pebble into a square
playing field. When one stone lands on another of the same color,
this stone as well as all bordering stones of the same color
disappear. The goal is, of course, to empty the field. A window above
the playing field shows which stone is going to come next. Knowing
which stone is going to follow is a deciding factor in the game's
strategy.

"Choosing the sequence of the moves with care is also very important:
a well positioned pebble can do more than just eliminate others; it
can also be the basis for up coming moves, just as a badly positioned
pebble can prove to be terribly obstructive. The level of difficulty
increases with the number of pebbles that are in the playing field at
the start of a game as well as the number of different colors."