"Advent calendars are not just for Christmas anymore. What a great build up to my favorite holiday, Halloween!" ♥♥♥ -AudreyB
Open a different portal on the mysterious Calloween house every day throughout October-2011 to reveal the creature behind each portal. Find monsters, spiders, and other creepy creatures.
And if you want to learn more about the monsters revealed by this app, look for the Android app, Monsterary, where you can learn about and mutate Monsters! (And Dinoary let's you learn about and mutate dinosaurs, along with learning their pronunciations!)
Oh, and if you want a less scary, day-time version of this app, look for Caloween™ (with one 'l').