Square Enix recently announced a new game in the Final Fantasy Tactics franchise, a strategy-based spinoff of the main Final Fantasy series.
According to website TUAW (via TouchArcade), this “S” seems to mean that the game will be social. Perhaps players will fight against others, or some other social or sharing aspect will come into the game.
I haven’t played a Square Enix game on iOS, but the report says that the company isn’t the best at working iOS controls into its games. Also, it’s only been announced for Japan at this point, but it’s most likely it will hit worldwide. Square Enix wants our money, after all.