A quick search through the App Store reveals over 300 hits for “chess.” Granted, not all of them are actually full-fledged chess apps, but nonetheless there are a great deal of them that are. Some are tactics, many are engines, some are two-player, even a few of them are database apps exclusively. The biggest complaint I see on forums is that many of these Apps don’t allow you an easy way to get games on or off of the device. What’s more, you can only rough the main lines of any games that your device may choose to load.
So that begs the question: why can’t we have variations on the iPhone? Answer: we can.