It seems like an iPhone app which is named Voice Fantasy and requires you to shout in order to summon dashing heroes should somehow be dirty, but it's actually an amusing game which you might enjoy on a dull evening.
The basic point of the game is to summon courageous heroes by shouting out their names. You choose the name and then the type of hero will be determined based on how you sound when you summon him or her. (As you can see by the video above, a loud and high-pitched shout will apparently bring you a masochist heroine.)
You can play against the in-game opponents as well as in one-on-one or two-on-two modes against your friends. I'd imagine that the game is far more likely to remain amusing after a few rounds if you are playing with a larger group rather than staying in solo mode. That's mostly because the entire battles are automated—whether you're in tutorial mode or not—and you remain a helpless spectator except when summoning characters.
With that in mind, note that the game's gonna run you three dollars. If it were a buck, then I'd recommend it for a few giggly shouting matches and competitions for better rankings with pals, but as that is not the case I'll simply caution you that the entertainment factor is somewhat limited in comparison to similarly priced apps. [iTunes]